Summary of perimeter and area of simple geometrical figure

Solved exercise of perimeter and area of simple geometrical figure

Summary

The sum of length of all the sides of a geometrical figure is called its perimeter.

Example: Planning the construction of a house. Since you have to pour a concrete foundation, within the housing constraints you want to maximize the area within the constraints which are related to the perimeter (like you can only get so close to a neighbor’s house, etc.)

Perimeter of simple geometrical figures

Some simple geometrical figures are

Exercises 1.1

Find the perimeter of the Geometrical figures.

GIVEN EF=3CM, FG=5CM ,GH=7CM ,HI=5CM ,IE=4CM                     Perimeter =  EF+  FG+ GH+ HI+ IE                       3CM+5CM+7CM+5CM+4CM                                 Perimeter=24CM

GIVEN JK8C, JN=2CM,KL=6CM, MN-5CM ML 6CM                      Perimeter= JK+ JN +KL+MN +ML                      8CM + 2CM+ 6CM+ 5CM+ 6CM Perimeter=27 cm

                            

Given PQ=4CM,QR=2CM,RS=2CM,ST=4CM,TU=3CM,PU=3CM                       Perimeter= PQ+QR+RS+ST+TUPU                      4CM+2CM=2CM+4CM+3CM+3CM                              Perimeter =  18CM

GIVEN= 7CM, XC=8CM, NC=4CM, RN=6CM, MR=3C MW=2CM                   Perimeter= WX+XC+NC+RN+MR+MW                     7cm+8cm+4cm+6cm+3cm+2cm       Perimeter =30CM.

  II. In list ‘A’ plane figures and in list ‘B’ their perimeters are given. Match list ‘A’ with list ‘B’

Exercise 1.2

Perimeter( sum of 4 sides) = 24cm

Sum of 3 sides        =22cm

Length of the 4^th side           =2cm

Sum of given 3 sides          = 2cm+ 10cm+ 10cm

       = 22cm

Length and four side = perimeter – sum of 3 sides

Length of 4^th side =24cm -22cm     =       22cm.

2.

Perimeter (sum of 5 sides)=24cm

=sum of 4 sides                     =19cm

Length of the 5 sides           =5cm

Sum of given 4 sides=3cm+ 4cm+ 4cm+ 8cm

     =19cm

Length and fifth side = perimeter-sum of 3 sides

Length of 5 sides =24cm -19cm   =5cm.

3.

In general area is expressed in square unit. ∴Units of Area : Sq cms, Sq mtrs, Sq kms… etc.

Example:

Count the number of squares inside the shape. Totally there are 7 squares. Area of given shape = 7 sq cm.

Exercise  1.3

On the graph sheet given, the area of each square is 1 sq cm. Find the area of the given shapes.

There are totally 5 square.

Area of given shape =5 sq cm

There are totally 21 square

Area of given shape=21 sq cm.

There are totally 16 Square

Area of given shape=16 sq cm.

There are totally 20 Square

Area of given shape=20 sq cm.

There are totally 12 Square

Area of given shape=12 sq cm.