{"id":2020,"date":"2020-11-30T14:44:59","date_gmt":"2020-11-30T14:44:59","guid":{"rendered":"https:\/\/themindpalace.in\/?p=2020"},"modified":"2021-08-26T05:34:57","modified_gmt":"2021-08-26T05:34:57","slug":"the-triangle-and-its-properties","status":"publish","type":"post","link":"https:\/\/themindpalace.in\/index.php\/2020\/11\/30\/the-triangle-and-its-properties\/","title":{"rendered":"The Triangle and its Properties"},"content":{"rendered":"\n<p id=\"exercise\"><a href=\"#solvedexercise\">Solved exercise on triangle and its properties<\/a><\/p>\n\n\n\n<p><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"433\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/properties-of-triangel-1024x433.jpg\" alt=\"\" class=\"wp-image-2062\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/properties-of-triangel-1024x433.jpg 1024w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/properties-of-triangel-300x127.jpg 300w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/properties-of-triangel-768x325.jpg 768w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/properties-of-triangel.jpg 1360w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/div>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"exercise\">Exercise<\/h1>\n\n\n\n<p><span class=\"has-inline-color has-vivid-red-color\">1. In \u2206PQR, D is the mid-pointof\u00a0QR<br>PM\u00a0is<\/span><br>PD\u00a0is<\/p>\n\n\n\n<p>&nbsp;If QM = MR?<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"215\" height=\"139\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/1-5.jpg\" alt=\"\" class=\"wp-image-2021\"\/><\/figure><\/div>\n\n\n\n<p><span class=\"has-inline-color has-vivid-purple-color\">Solution:<\/span><br>PM is altitude.<br>PD is median.<br>No, QM \u2260 MR.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><span class=\"has-inline-color has-vivid-red-color\">2. Draw rough sketches for the following<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"449\" height=\"196\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/2-1.jpg\" alt=\"\" class=\"wp-image-2022\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/2-1.jpg 449w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/2-1-300x131.jpg 300w\" sizes=\"(max-width: 449px) 100vw, 449px\" \/><\/figure><\/div>\n\n\n\n<p>(a) In \u2206ABC, BE is a median.<br>(b) In \u2206PQR, PQ and PR are altitudes of the triangle.<br>(c) In \u2206XYZ, YL is an altitude in the exterior of the triangle.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><span class=\"has-inline-color has-vivid-red-color\">3. Verify by drawing a diagram if the median and altitude of an isosceles triangle can be same.<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"201\" height=\"225\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/3-3.jpg\" alt=\"\" class=\"wp-image-2023\"\/><\/figure><\/div>\n\n\n\n<p>\u2206ABC is an isosceles triangle in which AB = AC<br>&nbsp;Draw AD as the median of the triangle.<br>Measure the angle ADC with the help of protractor we find, \u2220ADC = 90\u00b0<br>Thus, AD is the median as well as the altitude of the \u2206ABC. Hence Verified.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><strong><span class=\"has-inline-color has-vivid-purple-color\">Exercise 6.2<\/span><\/strong><\/p>\n\n\n\n<p><span style=\"color:#d207e1\" class=\"has-inline-color\">1. Find the value of the unknown exterior angle x in the following diagrams<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"192\" height=\"143\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/6.2-1.jpg\" alt=\"\" class=\"wp-image-2024\"\/><\/figure><\/div>\n\n\n\n<p><strong><span style=\"color:#f01338\" class=\"has-inline-color\">Solution<\/span><\/strong><\/p>\n\n\n\n<p>(i)\u2220x = 50\u00b0 + 70\u00b0<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = 120\u00b0<\/p>\n\n\n\n<p>(Exterior angle is equal to sum of its interior opposite angles)<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"174\" height=\"125\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/6.2b.jpg\" alt=\"\" class=\"wp-image-2025\"\/><\/figure><\/div>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(ii) \u2220x = 65\u00b0+ 45\u00b0<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = 110\u00b0<\/p>\n\n\n\n<p>(Exterior angle is equal to sum of its interior opposite angles)<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(iii) \u2220x = 30\u00b0 + 40\u00b0<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = 70\u00b0<\/p>\n\n\n\n<p>(Exterior angle is equal to sum of its interior opposite angles)<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"181\" height=\"119\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/6.2c.jpg\" alt=\"\" class=\"wp-image-2026\"\/><\/figure><\/div>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><br><\/p>\n\n\n\n<p>(iv) \u2220x = 60\u00b0 + 60\u00b0<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = 120\u00b0<\/p>\n\n\n\n<p>(Exterior angle is equal to sum of its interior opposite angles)<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"181\" height=\"119\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/6.2c-1.jpg\" alt=\"\" class=\"wp-image-2027\"\/><\/figure><\/div>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(v) \u2220x = 50\u00b0 + 50\u00b0<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; =100\u00b0<\/p>\n\n\n\n<p>(Exterior angle is equal to sum of its interior opposite angles)<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"161\" height=\"149\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/6.2-e.jpg\" alt=\"\" class=\"wp-image-2029\"\/><\/figure><\/div>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(vi) \u2220x = 30\u00b0 + 60\u00b0<\/p>\n\n\n\n<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = 90\u00b0<\/p>\n\n\n\n<p>&nbsp;(Exterior angle is equal to sum of its interior opposite angle)<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"166\" height=\"146\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/6.2-f-1.jpg\" alt=\"\" class=\"wp-image-2030\"\/><\/figure><\/div>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><strong><span style=\"color:#ee0bd7\" class=\"has-inline-color\">2. Find the value of the unknown interior angle x in the following figures:<\/span><\/strong><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"169\" height=\"159\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/2-find-value-of-unknown-1.jpg\" alt=\"\" class=\"wp-image-2031\"\/><\/figure><\/div>\n\n\n\n<p>(i) \u2220x + 50\u00b0 = 115\u00b0 (Exterior angle of a triangle)<br>\u2234 \u2220x = 115\u00b0- 50\u00b0 = 65\u00b0<br><br>(ii) \u2220x + 70\u00b0 = 110\u00b0 (Exterior angle of a triangle)<br>\u2234 \u2220x = 110\u00b0 \u2013 70\u00b0 = 40\u00b0<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"157\" height=\"149\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/2-unknown-2.jpg\" alt=\"\" class=\"wp-image-2032\"\/><\/figure><\/div>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(iii) \u2220 x + 90\u00b0 = 125\u00b0 (Exterior angle of a right triangle)<br>\u2234 \u2220x = 125\u00b0 \u2013 90\u00b0 = 35\u00b0<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"176\" height=\"156\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/2-unknown-3.jpg\" alt=\"\" class=\"wp-image-2033\"\/><\/figure><\/div>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(iv) \u2220x + 60\u00b0 = 120\u00b0 (Exterior angle of a triangle)<br>\u2234 \u2220x = 120\u00b0 \u2013 60\u00b0 = 60\u00b0<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"149\" height=\"137\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/2-unknown-4.jpg\" alt=\"\" class=\"wp-image-2034\"\/><\/figure><\/div>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(v)\u2220 X + 30\u00b0 = 80\u00b0 (Exterior angle of a triangle)<br>\u2234 \u2220x = 80\u00b0 \u2013 30\u00b0 = 50\u00b0<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"183\" height=\"147\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/2-unknown-5.jpg\" alt=\"\" class=\"wp-image-2035\"\/><\/figure><\/div>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(vi) \u2220 x + 35\u00b0 = 75\u00b0 (Exterior angle of a triangle)<br>\u2234 \u2220 x = 75\u00b0 \u2013 35\u00b0 = 40\u00b0<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"179\" height=\"126\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/2-unknown-6.jpg\" alt=\"\" class=\"wp-image-2036\"\/><\/figure><\/div>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><strong><span style=\"color:#b517b5\" class=\"has-inline-color\">Exercise 6.3<\/span><\/strong><\/p>\n\n\n\n<p><span style=\"color:#ed06f5\" class=\"has-inline-color\">1. Find the value of the unknown x in the following diagrams<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"235\" height=\"472\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/exercise-6.3-1.jpg\" alt=\"\" class=\"wp-image-2038\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/exercise-6.3-1.jpg 235w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/exercise-6.3-1-149x300.jpg 149w\" sizes=\"(max-width: 235px) 100vw, 235px\" \/><\/figure><\/div>\n\n\n\n<p><strong><span class=\"has-inline-color has-vivid-purple-color\">Solution:<\/span><\/strong>i) By angle sum property of a triangle, we have<br>\u2220x + 50\u00b0 + 60\u00b0 = 180\u00b0<br>\u21d2 \u2220x + 110\u00b0 = 180\u00b0<br>\u2234 \u2220x = 180\u00b0 \u2013 110\u00b0 = 70\u00b0<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(ii) By angle sum property of a triangle, we have<br>\u2220x + 90\u00b0 + 30 = 180\u00b0 [\u2206 is right angled triangle]<br>\u21d2 \u2220x + 120\u00b0 = 180\u00b0<br>\u2234 \u2220x \u2013 180\u00b0 \u2013 120\u00b0 = 60\u00b0<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(iii) By angle sum property of a triangle, we have<br>\u2220x + 30\u00b0 + 110\u00b0 \u2013 180\u00b0<br>\u21d2 \u2220x + 140\u00b0 = 180\u00b0<br>\u2234 \u2220x = 180\u00b0 \u2013 140\u00b0 = 40\u00b0<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><strong><span style=\"color:#ef09c9\" class=\"has-inline-color\">Find the value of the unknown x in the following diagrams<\/span><\/strong><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"194\" height=\"479\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/exercise-6.3-4-56.jpg\" alt=\"\" class=\"wp-image-2039\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/exercise-6.3-4-56.jpg 194w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/exercise-6.3-4-56-122x300.jpg 122w\" sizes=\"(max-width: 194px) 100vw, 194px\" \/><\/figure><\/div>\n\n\n\n<p><br><span class=\"has-inline-color has-vivid-purple-color\">Solution<\/span>:(iv ) By angle sum property of a triangle, we have<br>\u2220x + \u2220x + 50\u00b0 = 180\u00b0<br>\u21d2 2x + 50\u00b0 = 180\u00b0<br>\u21d2 2x = 180\u00b0 \u2013 50\u00b0<br>\u21d2 2x = 130\u00b0<br>\u2234&nbsp;x=130\/2=65\u2218<br>(v) By angle sum property of a triangle, we have<br>\u2220x + \u2220x +\u2220x =180\u00b0<br>\u21d2 3 \u2220x = 180\u00b0<br>\u2234&nbsp;\u2220x=180\/3=60\u2218<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(vi) By angle sum property of a triangle, we have<br>x + 2 x + 90\u00b0 = 180\u00b0 (\u2206 is right angled triangle)<br>\u21d2 3x + 90\u00b0 = 180\u00b0<br>\u21d2 3x = 180\u00b0 \u2013 90\u00b0<br>\u21d2 3x = 90\u00b0<br>\u2234&nbsp;x=90\/3=30\u2218<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><span style=\"color:#f506d5\" class=\"has-inline-color\">2. Find the values of the unknowns x and y in the following diagrams:<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"228\" height=\"417\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/exercise-6.3-2-problem.jpg\" alt=\"\" class=\"wp-image-2040\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/exercise-6.3-2-problem.jpg 228w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/exercise-6.3-2-problem-164x300.jpg 164w\" sizes=\"(max-width: 228px) 100vw, 228px\" \/><\/figure><\/div>\n\n\n\n<p><br>(i) \u2220x + 50\u00b0 = 120\u00b0 (Exterior angle of a triangle)<br>\u2234 \u2220x = 120\u00b0- 50\u00b0 = 70\u00b0<br>\u2220x + \u2220y + 50\u00b0 = 180\u00b0 (Angle sum property of a triangle)<br>70\u00b0 + \u2220y + 50\u00b0 = 180\u00b0<br>\u2220y + 120\u00b0 = 180\u00b0<br>\u2220y = 180\u00b0 \u2013 120\u00b0<br>\u2234 \u2220y = 60\u00b0<br>Thus \u2220x = 70 and \u2220y \u2013 60\u00b0<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(ii) \u2220y = 80\u00b0 (Vertically opposite angles are same)<br>\u2220x + \u2220y + 50\u00b0 = 180\u00b0 (Angle sum property of a triangle)<br>\u21d2 \u2220x + 80\u00b0 + 50\u00b0 = 180\u00b0<br>\u21d2 \u2220x + 130\u00b0 = 180\u00b0<br>\u2234 \u2220x = 180\u00b0 \u2013 130\u00b0 = 50\u00b0<br>Thus, \u2220x = 50\u00b0 and \u2220y = 80\u00b0<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><strong><span style=\"color:#eb08eb\" class=\"has-inline-color\">Find the values of the unknowns x and y in the following diagrams:<\/span><\/strong><\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"269\" height=\"416\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/exercise-6.3-2-34.jpg\" alt=\"\" class=\"wp-image-2041\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/exercise-6.3-2-34.jpg 269w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/exercise-6.3-2-34-194x300.jpg 194w\" sizes=\"(max-width: 269px) 100vw, 269px\" \/><\/figure>\n\n\n\n<p><br>(iii) \u2220y + 50\u00b0 + 60\u00b0 = 180\u00b0 (Angle sum property of a triangle)<br>\u2220y + 110\u00b0 = 180\u00b0<br>\u2234 \u2220y = 180\u00b0- 110\u00b0 = 70\u00b0<br>\u2220x + \u2220y = 180\u00b0 (Linear pairs)<br>\u21d2 \u2220x + 70\u00b0 = 180\u00b0<br>\u2234 \u2220x = 180\u00b0 \u2013 70\u00b0 = 110\u00b0<br>Thus, \u2220x = 110\u00b0 and y = 70\u00b0<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(iv) \u2220x = 60\u00b0 (Vertically opposite angles)<br>\u2220x + \u2220y + 30\u00b0 = 180\u00b0 (Angle sum property of a triangle)<br>\u21d2 60\u00b0 + \u2220y + 30\u00b0 = 180\u00b0<br>\u21d2 \u2220y + 90\u00b0 = 180\u00b0<br>\u21d2 \u2220y = 180\u00b0 \u2013 90\u00b0 = 90\u00b0<br>Thus, \u2220x = 60\u00b0 and \u2220y = 90\u00b0<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><span style=\"color:#f60aea\" class=\"has-inline-color\">Find the values of the unknowns x and y in the following diagrams:<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"339\" height=\"434\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/90.jpg\" alt=\"\" class=\"wp-image-2043\" srcset=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/90.jpg 339w, https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/90-234x300.jpg 234w\" sizes=\"(max-width: 339px) 100vw, 339px\" \/><\/figure><\/div>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(v) \u2220y = 90\u00b0 (Vertically opposite angles)<br>\u2220x + \u2220x + \u2220y = 180\u00b0 (Angle sum property of a triangle)<br>\u21d2 2 \u2220x + 90\u00b0 = 180\u00b0<br>\u21d2 2\u2220x = 180\u00b0 \u2013 90\u00b0<br>\u21d2 2\u2220x = 90\u00b0<br>\u2234&nbsp;\u2220x=90\/2=45\u2218<br>Thus, \u2220x = 45\u00b0 and \u2220y = 90\u00b0<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(vi) From the given figure, we have<br>&nbsp;<br>Adding both sides, we have<br>\u2220y + \u22201 + \u22202 = 3\u2220x<br>\u21d2 180\u00b0 = 3\u2220x (Angle sum property of a triangle)<br>\u2234&nbsp;\u2220x=180\/ 3=60\u2218<br>\u2220x = 60\u00b0, \u2220y = 60\u00b0<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><span style=\"color:#d70af2\" class=\"has-inline-color\"><strong>Exercise 6.4 &amp; 6.5<\/strong><\/span><\/p>\n\n\n\n<p><span style=\"color:#f00cdd\" class=\"has-inline-color\">1. Is it possible to have a triangle with the following sides?<\/span><\/p>\n\n\n\n<p>(i) 2 cm, 3 cm, 5 cm<br>(ii) 3 cm, 6 cm, 7 cm<br>(iii) 6 cm, 3 cm, 2 cm<\/p>\n\n\n\n<p>Solution:We know that for a triangle, the sum of any two sides must be greater than the third side.<\/p>\n\n\n\n<p>(i) Given sides are 2 cm, 3 cm, 5 cm<br>Sum of the two sides = 2 cm + 3 cm = 5 cm Third side = 5 cm<br>We have, Sum of any two sides = the third side i.e. 5 cm = 5 cm<br>Hence, the triangle is not possible.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(ii) Given sides are 3 cm, 6 cm, 7 cm<br>Sum of the two sides = 3 cm + 6 cm = 9 cm Third side = 7 cm<br>We have sum of any two sides &gt; the third<br>side. i.e. 9 cm &gt; 7 cm<br>Hence, the triangle is possible.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(iii) Given sides are 6 cm, 3 cm, 2 cm<br>Sum of the two sides = 3 cm + 2 cm \u2013 5 cm Third side = 6 cm<br>We have, sum of any two sides &lt; the third sid6 i.e. 5 cm &lt; 6 cm Hence, the triangle is not possible.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><span style=\"color:#f00ed2\" class=\"has-inline-color\">2. Take any point O in the interior of a triangle PQR . Is<\/span><\/p>\n\n\n\n<p>i) OP + OQ &gt; PQ?<br>(ii) OQ + OR &gt; QR?<br>(iii) OR + OP &gt; RP?<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"184\" height=\"120\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/6.41.jpg\" alt=\"\" class=\"wp-image-2045\"\/><\/figure><\/div>\n\n\n\n<p><span class=\"has-inline-color has-vivid-purple-color\">Solution<\/span>:(i) Yes, In \u2206 OPQ, we have<br>OP + OQ &gt; PQ<br>[Sum of any two sides of a triangle is greater than the third side]<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(ii) Yes, In \u2206OQR, we have OQ + OR &gt; QR<br>[Sum of any two sides of a triangle is greater than the third side]<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(iii) Yes, In \u2206OPR, we have OR + OP &gt; RP<br>[Sum of any two sides of a triangle is greater than the third side]<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><span style=\"color:#f404dc\" class=\"has-inline-color\">3. AM is a median of a triangle ABC.<\/span><br>Is AB + BC + CA &gt; 2AM ?<br>(Consider the sides of triangles \u2206ABM and \u2206AMC)<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"205\" height=\"163\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/2-2.jpg\" alt=\"\" class=\"wp-image-2046\"\/><\/figure><\/div>\n\n\n\n<p><br><strong><span class=\"has-inline-color has-vivid-purple-color\">Solution:<\/span><\/strong>Yes, In \u2206 ABM, we have<\/p>\n\n\n\n<p>AB + BM &gt; AM \u2026(i)<br>[Sum of any two sides of a triangle is greater than the third side]<br>In \u2206AMC, we have<br>AC + CM &gt; AM \u2026(ii)<br>[Sum of any two sides of a triangle is greater than the third side]<br>Adding eq (i) and (ii), we have<br>AB + AC + BM + CM &gt; 2AM<br>AB + AC + BC + &gt; 2AM<br>AB + BC + CA &gt; 2AM<br>Hence, proved.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>4. ABCD is a quadrilateral.<br>Is AB + BC + CD + DA &gt; AC + BD?<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"227\" height=\"169\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/4-5.jpg\" alt=\"\" class=\"wp-image-2048\"\/><\/figure><\/div>\n\n\n\n<p><strong><span class=\"has-inline-color has-vivid-purple-color\">Solution:<\/span><\/strong><\/p>\n\n\n\n<p>In \u2206ABC, we have<br>AB + BC &gt; AC \u2026(i)<br>[Sum of any two sides is greater than the third side]<br>In \u2206BDC, we have<br>BC + CD &gt; BD \u2026(ii)<br>[Sum of any two sides is greater than the third side]<br>In \u2206ADC, we have<br>CD + DA &gt; AC \u2026(iii)<br>[Sum of any two sides is greater than the third side]<br>In \u2206DAB, we have<br>DA + AB &gt; BD \u2026(iv)<br>[Sum of any two sides is greater than the third side]<br>Adding eq. (i), (ii), (iii) and (iv), we get<br>2AB + 2BC + 2CD + 2DA &gt; 2AC + 2BD or<\/p>\n\n\n\n<p>AB + BC + CD + DA &gt; AC + BD&nbsp;&nbsp;&nbsp; [Dividing both sides by 2]<br>Hence, proved.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><span style=\"color:#f107c6\" class=\"has-inline-color\">5. ABCD is a quadrilateral.<\/span><br>Is AB + BC + CD + DA &lt; 2(AC + BD)?<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"263\" height=\"168\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/5-5.jpg\" alt=\"\" class=\"wp-image-2049\"\/><\/figure><\/div>\n\n\n\n<p><span class=\"has-inline-color has-vivid-purple-color\">Solution:<\/span>we have a quadrilateral ABCD.<\/p>\n\n\n\n<p>In \u2206AOB, we have AB &lt; AO + BO \u2026(i)<br>[Any side of a triangle is less than the sum of other two sides]<br>In \u2206BOC, we have<br>BC &lt; BO + CO \u2026(ii)<br>[Any side of a quadrilateral is less than the sum of other two sides]<br>In \u2206COD, we have<br>CD &lt; CO + DO \u2026(iii)<br>[Any side of a triangle is less than the sum of other two sides]<\/p>\n\n\n\n<p>In \u2206AOD, we have<br>DA &lt; DO + AO \u2026(iv)<br>[Any side of a triangle is less than the sum of other two sides]<\/p>\n\n\n\n<p>Adding eq. (i), (ii), (iii) and (iv), we have<br>AB + BC + CD + DA<br>\u22202AO + \u2220BO + \u2220CO + \u2220DO<br>\u22202(AO + BO + CO + DO)<br>\u22202 [(AO + CO) + (BO + DO)]<br>\u22202(AC + BD)<br>Thus, AB + BC + CD + DA &lt; 2(AC + BD)<br>Hence, proved.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><span style=\"color:#fa0bfa\" class=\"has-inline-color\">6. The length of two sides of a triangle are 12 cm and 15 cm. Between what two measures should the length of the third side fall?<\/span><\/p>\n\n\n\n<p><span class=\"has-inline-color has-vivid-purple-color\">Solution:<\/span>Sum of two sides<br>= 12 cm + 15 cm = 27 cm<br>Difference of the two sides<br>= 15 cm \u2013 12 cm = 3 cm<br>\u2234 The measure of third side should fall between 3 cm and 27 cm.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><br><strong><span style=\"color:#e70d31\" class=\"has-inline-color\">Exercise 6.5<\/span><\/strong><\/p>\n\n\n\n<p><span style=\"color:#f712c1\" class=\"has-inline-color\">1. PQR is a triangle, right angled at P. If PQ = 10 cm and PR = 24 cm, find QR.<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"244\" height=\"150\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/11-1.jpg\" alt=\"\" class=\"wp-image-2050\"\/><\/figure><\/div>\n\n\n\n<p><span class=\"has-inline-color has-vivid-purple-color\">Solution<\/span>:In right angled triangle PQR, we have<br>QR<sup>2<\/sup>&nbsp;= PQ<sup>2<\/sup>&nbsp;+ PR<sup>2<\/sup>&nbsp;From Pythagoras property)<br>= (10)<sup>2<\/sup>&nbsp;+ (24)<sup>2<\/sup><br>= 100 + 576 = 676<br>\u2234 QR =&nbsp;\u221a676 = 26 cm<br>The, the required length of QR = 26 cm.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><span style=\"color:#f00cbb\" class=\"has-inline-color\">2. ABC is a triangle, right angled at C. If AB = 25 cm and AC = 7 cm, find BC.<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"268\" height=\"160\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/22-2.jpg\" alt=\"\" class=\"wp-image-2051\"\/><\/figure><\/div>\n\n\n\n<p><span class=\"has-inline-color has-vivid-purple-color\">Solution:<\/span>In right angled \u2206 ABC, we have<br>BC<sup>2<\/sup>&nbsp;+ (7)<sup>2<\/sup>&nbsp;= (25)<sup>2<\/sup>&nbsp;(By Pythagoras property)<br>\u21d2 BC<sup>2<\/sup>&nbsp;+ 49 = 625<br>\u21d2 BC<sup>2<\/sup>&nbsp;= 625 \u2013 49<br>\u21d2 BC<sup>2<\/sup>&nbsp;= 576<\/p>\n\n\n\n<p>\u2234 BC =&nbsp;\u221a576 = 24 cm<br>Thus, the required length of BC = 24 cm.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><span style=\"color:#fa08fa\" class=\"has-inline-color\">3. A 15 m long ladder reached a window 12 m high from the ground on placing it against a wall at a distance a. Find the distance of the foot of the ladder from the wall.<\/span><\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"236\" height=\"155\" src=\"https:\/\/themindpalace.in\/wp-content\/uploads\/2020\/11\/33-2.jpg\" alt=\"\" class=\"wp-image-2052\"\/><\/figure><\/div>\n\n\n\n<p><br><span class=\"has-inline-color has-vivid-purple-color\">Solution:<\/span>Here, the ladder forms a right angled triangle.<br>\u2234 a<sup>2<\/sup>&nbsp;+ (12)<sup>2<\/sup>&nbsp;= (15)<sup>2<\/sup>&nbsp;(By Pythagoras property)<br>\u21d2 a<sup>2<\/sup>+ 144 = 225<br>\u21d2 a2 = 225 \u2013 144<br>\u21d2 a<sup>2<\/sup>&nbsp;= 81<\/p>\n\n\n\n<p>\u2234 a =&nbsp;\u221a 81 &nbsp;= 9 m<br>Thus, the distance of the foot from the ladder = 9m<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p><span style=\"color:#ef0abe\" class=\"has-inline-color\">4. Which of the following can be the sides of a right triangle?<\/span><br>(i) 2.5 cm, 6.5 cm, 6 cm.<br>(ii) 2 cm, 2 cm, 5 cm.<br>(iii) 1.5 cm, 2 cm, 2.5 cm<\/p>\n\n\n\n<p><span class=\"has-inline-color has-vivid-purple-color\">Solution:<\/span>i) Given sides are 2.5 cm, 6.5 cm, 6 cm.<br>Square of the longer side = (6.5)<sup>2<\/sup>&nbsp;= 42.25 cm.<br>Sum of the square of other two sides<br>= (2.5)<sup>2<\/sup>&nbsp;+ (6)<sup>2<\/sup>&nbsp;= 6.25 + 36<br>= 42.25 cm.<br>Since, the square of the longer side in a triangle is equal to the sum of the squares of other two sides.<br>\u2234 The given sides form a right triangle.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(ii) Given sides are 2 cm, 2 cm, 5 cm .<br>Square of the longer side = (5)<sup>2<\/sup>&nbsp;= 25 cm Sum of the square of other two sides<br>= (2)<sup>2<\/sup>&nbsp;+ (2)<sup>2<\/sup>&nbsp;=4 + 4 = 8 cm<br>Since 25 cm \u2260 8 cm<br>\u2234 The given sides do not form a right triangle.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>(iii) Given sides are 1.5 cm, 2 cm, 2.5 cm<br>Square of the longer side = (2.5)<sup>2<\/sup>&nbsp;= 6.25 cm Sum of the square of other two sides<br>= (1.5)<sup>2<\/sup>&nbsp;+ (2)<sup>2<\/sup>&nbsp;= 2.25 + 4<br>Since 6.25 cm = 6.25 cm = 6.25 cm<br>Since the square of longer side in a triangle is equal to the sum of square of other two sides.<br>\u2234 The given sides form a right triangle.<\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n\n\n\n<p>5. A tree is broken at a height of 5 m from the ground and its top touches the ground at a distance of 12 m from the base of the tree . Find the original height of the tree.<br><\/p>\n\n\n\n<p><br><\/p>\n\n\n\n<hr class=\"wp-block-separator is-style-wide\"\/>\n","protected":false},"excerpt":{"rendered":"<p>Solved exercise on triangle and its properties Exercise 1. In \u2206PQR, D is the mid-pointof\u00a0QRPM\u00a0isPD\u00a0is &nbsp;If QM = MR? Solution:PM is altitude.PD is median.No, QM \u2260 MR. 2. Draw rough sketches for the following&#46;&#46;&#46;<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[116,475,14],"tags":[246,173,247],"cp_meta_data":{"_edit_lock":["1629956097:2"],"_last_editor_used_jetpack":["block-editor"],"_jetpack_related_posts_cache":["a:1:{s:32:\"8f6677c9d6b0f903e98ad32ec61f8deb\";a:2:{s:7:\"expires\";i:1774994903;s:7:\"payload\";a:3:{i:0;a:1:{s:2:\"id\";i:2779;}i:1;a:1:{s:2:\"id\";i:1190;}i:2;a:1:{s:2:\"id\";i:1983;}}}}"],"_edit_last":["2"]},"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/posts\/2020"}],"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=2020"}],"version-history":[{"count":8,"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/posts\/2020\/revisions"}],"predecessor-version":[{"id":2509,"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/posts\/2020\/revisions\/2509"}],"wp:attachment":[{"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/media?parent=2020"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/categories?post=2020"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/themindpalace.in\/index.php\/wp-json\/wp\/v2\/tags?post=2020"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}