Page 218 - New Medley 5 Semester 1

Example 1: Find the perimeter of the following:

(a) The rectangle with length = 12 cm and breadth = 10 cm

(b) The square with each side = 7.5 m

Solution: (a) We have l = 12 cm and b = 10 cm

\ P = 2(l + b) = 2(12 cm + 10 cm)

= 2 × 22 cm = 44 cm

(b) Side (a) = 7.5 m

\ P = 4a = 4 × 7.5 m = 30 m

Example 2: The perimeter of a square and a rectangle are equal
in measure. If the length and breadth of the rectangle

are 40 cm and 36 cm respectively, find the length of
each side of the square.

Solution: Here, length of the rectangle (l) = 40 cm

and breadth of the rectangle (b) = 36 cm

\ Perimeter of the rectangle = 2 × (l + b)

= 2 × (40 + 36) cm

= 2 × 76 cm = 152 cm

Since perimeter of a square = Perimeter of a rectangle

So, perimeter of the square = 152 cm

Perimeter 152
Hence, each side of the square = = cm = 38 cm
4 4
EXERCISE 6.1

A. Find the perimeter of each of the following figures:
1. 4 cm 2. 60 cm 3. 1.5 m 1.5 m
2 cm
2 cm
6 cm 1 cm 2 cm 1 cm 70 cm 30 cm
2 cm

2 cm 50 cm 5 m 5 m

1.5 m 1.5 m
2 cm
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