Page 88 - Mathematics_Std_4

Example 1

Find the perimeter of the following rectangle.

FOR ONLINE READING ONLY
40 cm

100 cm
Solution

Perimeter of the rectangle = length + width + length + width
= 100 cm + 40 cm + 100 cm + 40 cm
= 280 cm
Or

The rectangle has two sides with equal length and two sides
with equal width. The perimeter is given by
Perimeter of the rectangle = × 2 length + × 2 width
= × 2 100 + cm × 2 40 cm

= 200 cm + 80 cm
= 280 cm
Therefore, the perimeter of the rectangle is 280 cm.

Example 2

Find the perimeter of a rectangle of length 13 m and width
11 m.

Solution
Length = 13 m, width = 11 m
Perimeter of a rectangle = × 2 length + × 2 width

= 2 13 m + × 2 11m
×
= 26 m + 22 m
= 48 m
Therefore, the perimeter of the rectangle is 48 m.

81

07/11/2024 14:04:37
MATHEMATICS STD 4 PB 2024.indd 81 07/11/2024 14:04:37
MATHEMATICS STD 4 PB 2024.indd 81