{"id":1530,"date":"2020-11-05T07:06:33","date_gmt":"2020-11-05T07:06:33","guid":{"rendered":"http:\/\/themindpalace.in\/?p=1530"},"modified":"2021-08-26T05:30:58","modified_gmt":"2021-08-26T05:30:58","slug":"circles","status":"publish","type":"post","link":"https:\/\/themindpalace.in\/index.php\/2020\/11\/05\/circles\/","title":{"rendered":"Circles"},"content":{"rendered":"\n<p><a href=\"#summary\">Summary of circles<\/a><\/p>\n\n\n\n<p><a href=\"#solved exercise\">Solved exercise of circles<\/a><\/p>\n\n\n\n<figure class=\"wp-block-image alignfull size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"960\" height=\"720\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/Slide1.jpg\" alt=\"\" class=\"wp-image-1531\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/Slide1.jpg 960w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/Slide1-300x225.jpg 300w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/Slide1-768x576.jpg 768w\" sizes=\"(max-width: 960px) 100vw, 960px\" \/><\/figure>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"summary\">summary<\/h1>\n\n\n\n<p>A circle is a set of all points in a plane at a fixed distance from a fixed point in a plane. The fixed point is called the center of the circle. The fixed distance is called the radius of the circle.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-medium\"><img loading=\"lazy\" decoding=\"async\" width=\"261\" height=\"300\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/1-261x300.jpg\" alt=\"\" class=\"wp-image-1533\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/1-261x300.jpg 261w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/1.jpg 416w\" sizes=\"(max-width: 261px) 100vw, 261px\" \/><\/figure><\/div>\n\n\n\n<p><strong>Radius<\/strong>:The constant distance is called the radius.<\/p>\n\n\n\n<p><strong>Chord<\/strong>: The line joining two points on the circumference of the circle is called a chord. The longest chord is the diameter of the circle.<\/p>\n\n\n\n<p><strong>Diameter<\/strong>: The chord which is passing through the centre of the circle. It is the biggest chord in the circle . It is twice the radius.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-medium\"><img loading=\"lazy\" decoding=\"async\" width=\"152\" height=\"300\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/21-152x300.jpg\" alt=\"\" class=\"wp-image-1534\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/21-152x300.jpg 152w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/21.jpg 247w\" sizes=\"(max-width: 152px) 100vw, 152px\" \/><\/figure><\/div>\n\n\n\n<p><span class=\"has-inline-color has-vivid-purple-color\"><strong>Sector of a circle<\/strong>: <\/span>The region enclosed by two radii and the corresponding arc is called a sector of the circle.<\/p>\n\n\n\n<p><span class=\"has-inline-color has-vivid-purple-color\"><strong>Segment of the circle<\/strong>:<\/span> The region bounded by an arc and the corresponding chord is called the segment of the circle.<\/p>\n\n\n\n<p><strong><span class=\"has-inline-color has-vivid-purple-color\">Tangent<\/span><\/strong><\/p>\n\n\n\n<p>A tangent to a circle is a straight line which touches the circle at only one point. The point where the tangent touches the circle is called point of contact of the tangent to the circle.<\/p>\n\n\n\n<p>A tangent to a circle is a special case of a secant, when the two ends points of its corresponding chord coincides.<\/p>\n\n\n\n<p>(i) At any point on the circle there can be one and only one tangent.<br>(ii) The line containing the radius through the point of contact is called the normal to the circle at the point.<\/p>\n\n\n\n<p><span class=\"has-inline-color has-vivid-purple-color\"><strong>Number of Tangents from a Point to Circle<\/strong><\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-medium\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"122\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/3-300x122.jpg\" alt=\"\" class=\"wp-image-1535\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/3-300x122.jpg 300w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/3.jpg 596w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/figure><\/div>\n\n\n\n<p>(i)No tangent can be drawn from the point lying inside the circle, as shown in fig. (i)<\/p>\n\n\n\n<p><br>(ii) One and only one tangent can be drawn from a point lying on the circle, as shown in fig. (ii)<\/p>\n\n\n\n<p><br>(iii) Only two tangents can be drawn from an exterior point to a circle, as shown in fig. <\/p>\n\n\n\n<p><span class=\"has-inline-color has-vivid-red-color\">1.<strong>Tangent to a Circle&nbsp;<\/strong><\/span>: It is a line that intersects the circle at only one point.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-medium\"><img loading=\"lazy\" decoding=\"async\" width=\"170\" height=\"300\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/4-1-170x300.jpg\" alt=\"\" class=\"wp-image-1537\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/4-1-170x300.jpg 170w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/4-1.jpg 263w\" sizes=\"(max-width: 170px) 100vw, 170px\" \/><\/figure><\/div>\n\n\n\n<p>There is only one tangent at a point of the circle.<\/p>\n\n\n\n<p>No tangent can be drawn from a point inside the circle.<\/p>\n\n\n\n<p><span class=\"has-inline-color has-vivid-red-color\"><strong>Point of contact<\/strong>:<\/span> The common point between the circle and the tangent is called the point of contact. \u2018A\u2019<\/p>\n\n\n\n<p>The tangent at any point of a circle is perpendicular to the radius through the point of contact.<\/p>\n\n\n\n<p>The lengths of tangents drawn from an external point to a circle are equal.<\/p>\n\n\n\n<p><span style=\"color:#2b22df\" class=\"has-inline-color\">1.<strong>Secant<\/strong>:<\/span> A line which has only two points common to a circle is called the secant.<\/p>\n\n\n\n<p><span style=\"color:#2f35d3\" class=\"has-inline-color\"><strong>Theorem 1:<\/strong>&nbsp;<\/span>Prove that the tangent at any point of a circle is perpendicular to the radius through the point of contact.<br><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"292\" height=\"241\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/5.jpg\" alt=\"\" class=\"wp-image-1539\"\/><\/figure><\/div>\n\n\n\n<ul><li><strong>Given:<\/strong>&nbsp;XY is a tangent at point P to the circle with centre O.<\/li><li><strong>To prove:<\/strong>&nbsp;OP \u22a5 XY<\/li><li><strong>Construction:<\/strong>&nbsp;Take a point Q on XY other than P and join OQ<\/li><li><strong>Proof:<\/strong>&nbsp;If point Q lies inside the circle, then XY will become a secant and not a tangent to the circle<br>OQ &gt; OP<\/li><li>Since this happens with every point on the line XY except the point P. OP is the shortest of all the distances of the point O to the points of XY<br>OP \u22a5 XY \u2026[Shortest side is the perpendicular]<\/li><\/ul>\n\n\n\n<p><strong><span style=\"color:#b61d9a\" class=\"has-inline-color\">Theorem 2<\/span><\/strong><span style=\"color:#134e20\" class=\"has-inline-color\"><strong>:<\/strong>&nbsp;<\/span>Prove that the lengths of tangents drawn from an external point to a circle are equal<br><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/6.jpg\" alt=\"\" class=\"wp-image-1542\" width=\"296\" height=\"235\"\/><\/figure><\/div>\n\n\n\n<ul><li><strong>Given:<\/strong>&nbsp;PT and PS are tangents from an external point P to the circle with centre O.<\/li><li><strong>To prove:<\/strong>&nbsp;PT = PS<\/li><li><strong>Construction:<\/strong>&nbsp;Join O to P, T and S.<\/li><li><strong>Proof:<\/strong>&nbsp;In \u2206OTP and \u2206OSP.<br>OT = OS \u2026[radii of the same circle]<br>OP = OP \u2026[common]<br>\u2220OTP = \u2220OSP \u2026[each 90\u00b0]<br>\u2206OTP = \u2206OSP \u2026[R.H.S.]<br>PT = PS \u2026[c.p.c.t.]<\/li><\/ul>\n\n\n\n<p><strong><span style=\"color:#7423bc\" class=\"has-inline-color\">Hence proved.<\/span><\/strong><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"428\" height=\"250\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/7-1.jpg\" alt=\"\" class=\"wp-image-1543\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/7-1.jpg 428w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/7-1-300x175.jpg 300w\" sizes=\"(max-width: 428px) 100vw, 428px\" \/><\/figure><\/div>\n\n\n\n<p><span class=\"has-inline-color has-luminous-vivid-orange-color\"><strong>Note:<\/strong>&nbsp;<\/span>If two tangents are drawn to a circle from an external point, then: \u2022They subtend equal angles at the centre i.e., \u22201 = \u22202. \u2022They are equally inclined to the segment joining the centre to that point i.e., \u22203 = \u22204.<br>\u2220OAP = \u2220OAQ<\/p>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"exercise\"><span style=\"color:#d422de\" class=\"has-inline-color\"><strong>Exercise 4.1<\/strong><\/span><\/h1>\n\n\n\n<p>1. How many tangents can a circle have?<\/p>\n\n\n\n<p>Solution:There can be infinitely many tangents to a circle.<\/p>\n\n\n\n<p><strong><span style=\"color:#de0d5d\" class=\"has-inline-color\">2. Fill in the blanks<\/span><\/strong><\/p>\n\n\n\n<p>(i)A tangent to a circle intersects it in &nbsp;&nbsp;<span class=\"has-inline-color has-vivid-purple-color\"><strong>One\u2026<\/strong>point(s)<\/span>.<\/p>\n\n\n\n<p><br>(ii) A line intersecting a circle in two points is called a <span class=\"has-inline-color has-vivid-purple-color\"><strong>Secant<\/strong>\u2026\u2026\u2026<\/span> .<\/p>\n\n\n\n<p><br>(iii) A circle can hav<span class=\"has-inline-color has-vivid-purple-color\">e \u2026<strong>Two<\/strong>\u2026<\/span> parallel tangents at the most.<\/p>\n\n\n\n<p><br>(iv) The common point of a tangent to a circle and the circle is called \u2026<strong><span class=\"has-inline-color has-vivid-purple-color\">Point of contact\u2026\u2026.. .<\/span><\/strong><\/p>\n\n\n\n<p><span style=\"color:#d51fd2\" class=\"has-inline-color\">2<\/span><span style=\"color:#274dd6\" class=\"has-inline-color\">.<\/span><span style=\"color:#ec12c4\" class=\"has-inline-color\"> A tangent PQ at a point P of a circle of radius 5 cm meets a line through the centre O at a point Q so that OQ = 12 cm. Length PQ is<\/span><\/p>\n\n\n\n<p>(a) 12 cm&nbsp;&nbsp;&nbsp; (b) 13 cm&nbsp;&nbsp;&nbsp; (c) 8.5 cm&nbsp;&nbsp; (d)&nbsp;\u221a119&nbsp;cm<\/p>\n\n\n\n<p><span style=\"color:#2131c5\" class=\"has-inline-color\">Solution:<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"252\" height=\"147\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/2-prb-1.jpg\" alt=\"\" class=\"wp-image-1545\"\/><\/figure><\/div>\n\n\n\n<p>Radius of the circles=5cm<\/p>\n\n\n\n<p>oQ-12 cm<\/p>\n\n\n\n<p>opq =90<\/p>\n\n\n\n<p>(The tengent to a circles is perpendicular to the radiusthrough the point of contact)<\/p>\n\n\n\n<p>Pq<sup>2<\/sup>=oq<sup>2<\/sup>-op<sup>2<\/sup>(by Pythagoras theorem)<\/p>\n\n\n\n<p>Pq<sup>2<\/sup>=12<sup>2<\/sup>-5<sup>2<\/sup>=144-25=199<\/p>\n\n\n\n<p>Pq=\u221a199 cm<\/p>\n\n\n\n<p>Hence correct option is (d)<\/p>\n\n\n\n<p><span style=\"color:#da1ca4\" class=\"has-inline-color\">4. Draw a circle and two lines parallel to a given line such that one is a tangent and the other, a secant to the circle.<\/span><\/p>\n\n\n\n<p><span class=\"has-inline-color has-vivid-purple-color\">Solution:<\/span>Here the given line CD is tangent to the given circle at the point M and parallel to AB and Ef is secent parallel to parallel to AB<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"204\" height=\"232\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/9.jpg\" alt=\"\" class=\"wp-image-1546\"\/><\/figure><\/div>\n\n\n\n<p><span style=\"color:#e234b6\" class=\"has-inline-color\"><strong>Exercise 4.2<\/strong><\/span><\/p>\n\n\n\n<p><span style=\"color:#c720c4\" class=\"has-inline-color\">In Q.1 to 3 choose the correct option and give justification<\/span><\/p>\n\n\n\n<p>1. From a point Q, the length of the tangent to a circle is 24 cm and the distance &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;of Q from the centre is 25 cm. The radius of the circle is<\/p>\n\n\n\n<p><strong>a) 7 cm&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <\/strong>(b) 12 cm&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (c) 15 cm&nbsp;&nbsp;&nbsp;&nbsp; (d) 24.5 cm<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"227\" height=\"155\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/new.jpg\" alt=\"\" class=\"wp-image-1919\"\/><\/figure><\/div>\n\n\n\n<p>The correct option is (A)<\/p>\n\n\n\n<p>Justification:<\/p>\n\n\n\n<p>Let OT be x cm.<\/p>\n\n\n\n<p>Then in right \u0394QTO,<\/p>\n\n\n\n<p>QO<sup>2<\/sup>=QT<sup>2<\/sup>+OT<sup>2<\/sup><\/p>\n\n\n\n<p><sup>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <\/sup>(By Pythagoras\u2019s Theorem)<\/p>\n\n\n\n<p>=(25)<sup>2<\/sup>=(24)<sup>2<\/sup>+x<sup>2<\/sup><\/p>\n\n\n\n<p>=x<sup>2<\/sup>=625-576=49<\/p>\n\n\n\n<p><strong>=x=<\/strong><strong>\u221a<\/strong><strong>49=7cm<\/strong><\/p>\n\n\n\n<p><span style=\"color:#dd21e0\" class=\"has-inline-color\">2. In figure, if TP and TQ are the two tangents to a circle with centre O so that \u2220POQ = 110\u00b0, then \u2220PTQ is equal to<\/span><\/p>\n\n\n\n<p>a) 60\u00b0&nbsp;&nbsp;&nbsp;&nbsp; <strong>(b) 70\u00b0&nbsp;&nbsp;&nbsp;&nbsp; <\/strong>(c) 80\u00b0&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (d) 90\u00b0<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"155\" height=\"126\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/exercise22-1.jpg\" alt=\"\" class=\"wp-image-1549\"\/><\/figure><\/div>\n\n\n\n<p>\u221a OPT=90<sup>0<\/sup><\/p>\n\n\n\n<p>\u221aOQT=90<sup>0<\/sup><\/p>\n\n\n\n<p>\u221aPOQ=110<sup>0<\/sup><\/p>\n\n\n\n<p>TPOQ is a quadrilateral,<\/p>\n\n\n\n<p>Therefore \u221aPTQ+\u221aPOQ=180<sup>0<\/sup><\/p>\n\n\n\n<p>=\u221aPTQ=180<sup>o<\/sup>-110<sup>0<\/sup>=70<sup>0<\/sup><\/p>\n\n\n\n<p><strong>Hence, correct option is (b)<\/strong><\/p>\n\n\n\n<p><span style=\"color:#dc0c63\" class=\"has-inline-color\">3. If tangents PA and PB from a point P to a circle with centre O are inclined to each other at angle of 80\u00b0, then \u2220POA is equal to<\/span><\/p>\n\n\n\n<p><strong>(a) 50<\/strong>\u00b0&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (b) 60\u00b0&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (c) 70\u00b0&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (d) 80\u00b0<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"201\" height=\"204\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/33-1.jpg\" alt=\"\" class=\"wp-image-1920\"\/><\/figure><\/div>\n\n\n\n<p>The correct option I (A)<\/p>\n\n\n\n<p>Justification:<\/p>\n\n\n\n<p>In \u0394POA and \u0394POB,<\/p>\n\n\n\n<p><strong>\u221a<\/strong>PAO=\u221aPBO<\/p>\n\n\n\n<p>OA=OB<\/p>\n\n\n\n<p>PA=PB<\/p>\n\n\n\n<p>\u0394POA=\u0394POB<\/p>\n\n\n\n<p>=\u221aAPO=\u221aBPO<\/p>\n\n\n\n<p>=\u221aAPO=1\/2 \u221aAPB=1\/2X80<sup>0<\/sup>=40<sup>0<\/sup><\/p>\n\n\n\n<p>In \u0394PAO, \u221aAPO+\u221aPOA+\u221aOAP=180<sup>0<\/sup><\/p>\n\n\n\n<p>=40<sup>0<\/sup>+\u221aPOA+90<sup>0<\/sup>=180<sup>0<\/sup><\/p>\n\n\n\n<p><strong>\u221aPOA=50<sup>0<\/sup><\/strong><\/p>\n\n\n\n<p><span style=\"color:#d00f43\" class=\"has-inline-color\">4. Prove that the tangents drawn at the ends of a diameter of a circle are parallel.<\/span><\/p>\n\n\n\n<p><span style=\"color:#3e18d5\" class=\"has-inline-color\">Solution:<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"400\" height=\"244\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/4-2.jpg\" alt=\"\" class=\"wp-image-1553\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/4-2.jpg 400w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/4-2-300x183.jpg 300w\" sizes=\"(max-width: 400px) 100vw, 400px\" \/><\/figure><\/div>\n\n\n\n<p>5<span style=\"color:#e32054\" class=\"has-inline-color\">. Prove that the perpendicular at the point of contact to the tangent to a circle passes through the centre.<\/span><\/p>\n\n\n\n<p>Solution:<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"204\" height=\"168\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/55-1.jpg\" alt=\"\" class=\"wp-image-1555\"\/><figcaption><br><br><br><br><\/figcaption><\/figure><\/div>\n\n\n\n<p>In the given figure AxB is the tangents o a circle with o<br>Here OX is the line perpendicular to the tangent AxB at the point of context X<br>The we have<br>OXB+BXY=90<sup>0<\/sup>+90<sup>0<\/sup>=180<sup>0<\/sup><br>Oxy is collinear I,e ox passes through the centre of the circle<br>Hence proved.<\/p>\n\n\n\n<p><span style=\"color:#e61dc1\" class=\"has-inline-color\">6.The length of a tangent from a point A at distance 5 cm from the centre of the circle is 4 cm. Find the radius of the circle.<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"258\" height=\"142\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/66.jpg\" alt=\"\" class=\"wp-image-1557\"\/><\/figure><\/div>\n\n\n\n<p>OA=5CM, AP=4CM<\/p>\n\n\n\n<p>OP=Radius of the circle<\/p>\n\n\n\n<p>\u221aOPA=90<sup>0<\/sup>(Radius and tangents are perpendicular)<\/p>\n\n\n\n<p>OA<sup>2<\/sup>=AP<sup>2<\/sup>+OP<sup>2<\/sup> (By Pythagoras theorem)<\/p>\n\n\n\n<p>5<sup>2<\/sup>=4<sup>2<\/sup>+op<sup>2<\/sup>=25=16+op<sup>2<\/sup><\/p>\n\n\n\n<p>=25-16=op2=9=OP<sup>2<\/sup>=\u221a9=OP<\/p>\n\n\n\n<p>=OP=3CM<\/p>\n\n\n\n<p><strong>RADIUS =3CM<\/strong><\/p>\n\n\n\n<p><span style=\"color:#e113a6\" class=\"has-inline-color\">7. Two concentric circles are of radii 5 cm and 3 cm. Find the length of the chord of the larger circle which touches the smaller circle.<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"261\" height=\"234\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/concentric-circle.jpg\" alt=\"\" class=\"wp-image-1561\"\/><\/figure><\/div>\n\n\n\n<p>Given: radii 5 cm and 3 cm<\/p>\n\n\n\n<p>To Find: length of the chord of the larger circle<\/p>\n\n\n\n<p><span class=\"has-inline-color has-luminous-vivid-orange-color\">Solution<\/span>:Consider a \u2206 OAP it is right angle at P [ by theorem radius is \ua4d5 to tangent]<\/p>\n\n\n\n<p>By pythagoras theorem,<\/p>\n\n\n\n<p>OA<sup>2<\/sup> = OP<sup>2<\/sup> + AP<sup>2<\/sup>                     Consider a \u2206 OPB<\/p>\n\n\n\n<p>5<sup>2<\/sup> = 3<sup>2 <\/sup>+ AP<sup>2<\/sup>                            OB<sup>2<\/sup> = OP<sup>2<\/sup> + BP<sup>2<\/sup><\/p>\n\n\n\n<p>AP<sup>2<\/sup> = 25 \u2013 9                              5<sup>2<\/sup> = 3<sup>2 <\/sup>+ BP<sup>2<\/sup><\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;                                                                     <\/p>\n\n\n\n<p>AP<sup>2<\/sup> = 25 \u2013 9                         BP<sup>2<\/sup> = 25 \u2013 9<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = 16                                 = 16<\/p>\n\n\n\n<p>AP = \u221a16                             BP = \u221a16<\/p>\n\n\n\n<p>AP = 4 cm.                     BP = 4 cm.<\/p>\n\n\n\n<p><strong>\u2234 <\/strong>AP + BP = 4 + 4 = 8 cm.<\/p>\n\n\n\n<p>&nbsp;<strong>\u2234 A chord AB = 8 cm.<\/strong><\/p>\n\n\n\n<p>AP = 4 cm.<\/p>\n\n\n\n<p><span style=\"color:#f116a1\" class=\"has-inline-color\">8. A quadrilateral ABCD is drawn to circumscribe a circle (see figure). Prove that AB + CD = AD + BC.<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"232\" height=\"196\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/88.jpg\" alt=\"\" class=\"wp-image-1562\"\/><\/figure><\/div>\n\n\n\n<p>Solution:AP = AS \u2026\u2026\u2026(1)<\/p>\n\n\n\n<p>[Lengths of a tangents from an external point are equal by theorem]<\/p>\n\n\n\n<p>BP = BQ \u2026\u2026\u2026(ii)<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp; CR = CQ\u2026\u2026\u2026(iii)<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp; CR = DS\u2026\u2026\u2026(iv)<\/p>\n\n\n\n<p>Adding equations (i), (ii), (iii) and (iv), we get<\/p>\n\n\n\n<p>AP + BP + CR + DR = AS + BQ + CQ + DS<\/p>\n\n\n\n<p>( AP + BP) + (CR + DR) = (AS + DS) + (BQ + CQ)<\/p>\n\n\n\n<p>AB= CD = AD + BC<\/p>\n\n\n\n<p><span class=\"has-inline-color has-vivid-red-color\">Hence proved.<\/span><\/p>\n\n\n\n<p><span style=\"color:#f32883\" class=\"has-inline-color\">9. In figure, XY and X\u2019Y\u2019 are two parallel tangents to a circle , x with centre O and another tangent AB with point of contact C intersecting XY at A and X\u2019Y\u2019 at B. Prove that \u2220AOB = 90\u00b0.<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"282\" height=\"203\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/99.jpg\" alt=\"\" class=\"wp-image-1563\"\/><\/figure><\/div>\n\n\n\n<p>Given: XY and X\u2019Y\u2019 are two parallel tangents to a circle &amp; another tangent AB with point of contact C<\/p>\n\n\n\n<p>To Prove: \u2220AOB = 90\u00b0.<\/p>\n\n\n\n<p>Solution:In a quadrilateral PABQ<\/p>\n\n\n\n<p>\u2220P + \u2220B + \u2220A + \u2220Q =360<sup>0<\/sup><\/p>\n\n\n\n<p>90<sup>0<\/sup> + 2x + 2y + 90<sup>0<\/sup> = 360<sup>0<\/sup><\/p>\n\n\n\n<p>2 (X + y) = 360 -180<sup>0<\/sup> =180<sup>0<\/sup><\/p>\n\n\n\n<p><strong>X + Y = 90<sup>0<\/sup><\/strong><\/p>\n\n\n\n<p>In \u2206 ABD<\/p>\n\n\n\n<p>\u2220A + \u2220O +\u2220 B = 180<sup>0<\/sup><\/p>\n\n\n\n<p>\u21d2X +\u2220O + Y = 180<sup>0<\/sup><\/p>\n\n\n\n<p>\u21d2X + y +\u2220O = 180<sup>0<\/sup><\/p>\n\n\n\n<p>\u21d290<sup>0<\/sup> +\u2220O = 180<sup>0<\/sup><\/p>\n\n\n\n<p>\u21d2\u2220O= 180<sup>0<\/sup> &#8211; 90<sup>0<\/sup><\/p>\n\n\n\n<p><strong>\u2234 \u2220O =&nbsp; 90<sup>0<\/sup><\/strong><\/p>\n\n\n\n<p><span style=\"color:#e828db\" class=\"has-inline-color\">10. Prove that the angle between the two tangents drawn from an external point to a circle is supplementary to the angle subtended by the line segment joining the points of contact at the centre.<\/span><\/p>\n\n\n\n<p><strong><span class=\"has-inline-color has-vivid-purple-color\">Solution<\/span><\/strong><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"239\" height=\"178\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/0-1.jpg\" alt=\"\" class=\"wp-image-1568\"\/><\/figure><\/div>\n\n\n\n<p>PA and PB are two tangents A and B are the points of contact of the tangent<\/p>\n\n\n\n<p>Pa and PB are two tangents &nbsp;A and B are the points of contact of the tangents<\/p>\n\n\n\n<p>OA is perpendicular AP and obis perpendicular to BP<\/p>\n\n\n\n<p>Angel OAP=angles OBP =90<\/p>\n\n\n\n<p>Radium and tangents are perpendicular to each other.<\/p>\n\n\n\n<p>P in quadrilateral OAPB<\/p>\n\n\n\n<p>OAP +OBP+APB+AOB=360<\/p>\n\n\n\n<p>=90+90+APB+AOB=360<\/p>\n\n\n\n<p>APB+AOB=360-180=180<\/p>\n\n\n\n<p>Hence APB and AOB are supplementary angles.<\/p>\n\n\n\n<p><span style=\"color:#e20d46\" class=\"has-inline-color\">11. Prove that the parallelogram circumscribing a circle is a rhombus<\/span><\/p>\n\n\n\n<p><span class=\"has-inline-color has-vivid-purple-color\">Solution:<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"267\" height=\"190\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/111.jpg\" alt=\"\" class=\"wp-image-1571\"\/><figcaption><br><\/figcaption><\/figure><\/div>\n\n\n\n<p>ABCD is a parallelogram therefore<\/p>\n\n\n\n<p>AB=CD&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (1)<\/p>\n\n\n\n<p>BC=AB&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (2)<\/p>\n\n\n\n<p>We know that the tangents drawn from same external point to circle are equal<\/p>\n\n\n\n<p>DR=DS&nbsp; (Tangents drawns from point D)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (3)<\/p>\n\n\n\n<p>CR=CQ (Tangents drawns from point C)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (4)<\/p>\n\n\n\n<p>BP=BQ (Tangents drawns from point C)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (5)<\/p>\n\n\n\n<p>AP=As (Tangents drawns from point A)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (6)<\/p>\n\n\n\n<p>Adding (3) and (5),(5) and (6) we have<\/p>\n\n\n\n<p>DR+CR+BP+AP=DS+CQ+BQ+AS<\/p>\n\n\n\n<p>=(DR+CR)+(BP+AP)=(DS+AS)+(CS+DQ)<\/p>\n\n\n\n<p>=CD+AB=AD+BC<\/p>\n\n\n\n<p>From (1)and 2 we have<\/p>\n\n\n\n<p>2AB=2BC=AB=BC<\/p>\n\n\n\n<p>FROM (1),(2)AND (7) WE HAVE<\/p>\n\n\n\n<p>AB=BC=CD=DA<\/p>\n\n\n\n<p>Hence ABCD IS A RHOMBUS<\/p>\n\n\n\n<p><span style=\"color:#e20a39\" class=\"has-inline-color\">12. A triangle ABC is drawn to circumscribe a circle of radius 4 cm such that the segments BD and DC into which BC is divided by the point of contact D are of lengths 8 cm and 6 cm respectively (see figure). Find the sides AB and AC.<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"286\" height=\"271\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/12.jpg\" alt=\"\" class=\"wp-image-1574\"\/><\/figure><\/div>\n\n\n\n<p>BD=8CM AND DC=6CM<\/p>\n\n\n\n<p>BE=BD=8CM<\/p>\n\n\n\n<p>CD=CF=6CM<\/p>\n\n\n\n<p>Let AE=AF=XCM<\/p>\n\n\n\n<p>IN ABC, A=6+8=14CM<\/p>\n\n\n\n<p>B=(X+6)CM<\/p>\n\n\n\n<p>C=(X+8) CM<\/p>\n\n\n\n<p>S=a+b+c\/2=14+x+6+x+8\/2=2x+28\/2=(x+14)cm<\/p>\n\n\n\n<p>Ar(ABC)=\u221aS(S-a)(s-b)(s-c)<\/p>\n\n\n\n<p>=\u221a(x+14)xx+8+6=\u221a48xX(x+14)cm<sup>2<\/sup><\/p>\n\n\n\n<p><sup>ar(ABC)=AR(OBC)+AR(OCA)+AR(OAB)<\/sup><\/p>\n\n\n\n<p><sup>=1\/2x4XA+1\/2X4XB+1\/2X4XC<\/sup><\/p>\n\n\n\n<p><sup>=2A+2B+2C=2(A+B+C)=2X2(X+14)<\/sup><\/p>\n\n\n\n<p>From (i) and (ii), we get<\/p>\n\n\n\n<p>\u221a48x(x+14)=4(x+14)=48x(x+14)=4<sup>2<\/sup>(x+14)<sup>2<\/sup><\/p>\n\n\n\n<p>=48x(x+14)=16(x+14)<sup>2<\/sup>=3x(x+14)=(x+14)<sup>2<\/sup><\/p>\n\n\n\n<p>=3x=x+14=2x=14=x=7<\/p>\n\n\n\n<p>AB=X=8=7+8=15CM<\/p>\n\n\n\n<p><strong>AC=X+6=7+6=13CM<\/strong><\/p>\n\n\n\n<p><span style=\"color:#d323d6\" class=\"has-inline-color\">13. Prove that opposite sides of a quadrilateral circumscribing a circle subtend supplementary angles at the centre of the circle.<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"121\" height=\"109\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/1111.jpg\" alt=\"\" class=\"wp-image-1580\"\/><\/figure><\/div>\n\n\n\n<p>From the figure we observe that OA bisects<\/p>\n\n\n\n<p>\u02c2SOP.<\/p>\n\n\n\n<p>So \u02c2a= \u02c2b&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (1)<\/p>\n\n\n\n<p>similarly \u02c2c= \u02c2d&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (2)<\/p>\n\n\n\n<p>\u02c2e= \u02c2f&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (3)<\/p>\n\n\n\n<p>\u02c2g= \u02c2h&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (4)<\/p>\n\n\n\n<p>Therefore 2(\u02c2a+\u02c2h+\u02c2e+\u02c2d)= 360<\/p>\n\n\n\n<p>=(\u02c2a+\u02c2h+\u02c2e+\u02c2d)=180<\/p>\n\n\n\n<p>=(\u02c2a+\u02c2h+\u02c2e+\u02c2d)=AOB+(\u02c2a+\u02c2h+\u02c2e+\u02c2d)=DOC=180<\/p>\n\n\n\n<p>Similarly \u02c2AOB +BOC)=180<\/p>\n\n\n\n<p>Thus opposites sides of quadrilaterals ABCD SUBSTEND SUPPLEMENTARY angles at the Center of the circle of a circle.<\/p>\n\n\n\n<p>hence proved.<\/p>\n\n\n\n<p><span style=\"color:#d11570\" class=\"has-inline-color\">Example: two tangents TP and TQ are drawn to circle with centre 0 from an external point T. Prove that PTQ=2\u02c2OPQ.<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"178\" height=\"102\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/lastone.jpg\" alt=\"\" class=\"wp-image-1584\"\/><\/figure><\/div>\n\n\n\n<p>Given:&nbsp; TP = TQ<\/p>\n\n\n\n<p>TO PROVE PTQ=2\u02c2OPQ<\/p>\n\n\n\n<p>SOLUTION:In \u2206 TPQ, TP = TQ<\/p>\n\n\n\n<p>\u22203 = \u22202, \u2026\u2026\u2026(I)[corresponding angles of an isosceles triangle]<\/p>\n\n\n\n<p>Now PT is a tangent and OP is radius<\/p>\n\n\n\n<p>Therefore, OP \ua4d5 TP<\/p>\n\n\n\n<p>So, \u2220OPT = 90<sup>0<\/sup><\/p>\n\n\n\n<p>\u22202 + \u22204 = 90<sup>0<\/sup> ,\u22202 = 90<sup>0<\/sup> \u2013 \u22204\u2026\u2026\u2026..(ii<\/p>\n\n\n\n<p>In \u2206 TPQ, \u2220T + \u2220P +\u2220 Q = 180<sup>0<\/sup><\/p>\n\n\n\n<p>From (i), (ii) &amp; (iii)<\/p>\n\n\n\n<p>\u22201 + \u22202 + \u22202 = 180<sup>0<\/sup><\/p>\n\n\n\n<p>\u22201 + 2\u22202= 180<sup>0<\/sup><\/p>\n\n\n\n<p>\u22201 + 2( 90 -\u22204) = 180<sup>0<\/sup> [ from (ii)]<\/p>\n\n\n\n<p>\u22201 + 2x 90) \u2013 2 \u22204&nbsp; = 180<sup>0<\/sup><\/p>\n\n\n\n<p>&nbsp;&nbsp; \u22201 + 180<sup>0<\/sup> \u2013 2 \u22204&nbsp; = 180<sup>0<\/sup><\/p>\n\n\n\n<p>\u22201 = &nbsp;2 \u22204<\/p>\n\n\n\n<p>Hence proved<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Summary of circles Solved exercise of circles summary A circle is a set of all points in a plane at a fixed distance from a fixed point in a plane. The fixed point is&#46;&#46;&#46;<\/p>\n","protected":false},"author":3,"featured_media":1531,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[112,475,14],"tags":[187,189,188],"cp_meta_data":{"_edit_lock":["1629955858:2"],"_edit_last":["2"],"_layout":["inherit"],"_oembed_95287caaddeb112cd4edfcbd8e525566":["<iframe title=\"Introduction of Computers  Part1\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/SzIGR3gp_F4?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen><\/iframe>"],"_oembed_time_95287caaddeb112cd4edfcbd8e525566":["1604498472"],"_thumbnail_id":["1531"],"_last_editor_used_jetpack":["block-editor"],"_jetpack_related_posts_cache":["a:1:{s:32:\"8f6677c9d6b0f903e98ad32ec61f8deb\";a:2:{s:7:\"expires\";i:1776180548;s:7:\"payload\";a:3:{i:0;a:1:{s:2:\"id\";i:2176;}i:1;a:1:{s:2:\"id\";i:2618;}i:2;a:1:{s:2:\"id\";i:2124;}}}}"]},"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/Slide1.jpg","jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/posts\/1530"}],"collection":[{"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/comments?post=1530"}],"version-history":[{"count":17,"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/posts\/1530\/revisions"}],"predecessor-version":[{"id":2529,"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/posts\/1530\/revisions\/2529"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/media\/1531"}],"wp:attachment":[{"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/media?parent=1530"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/categories?post=1530"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/tags?post=1530"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}