Page 103 - Mathematics_Std_4

Example 2

A book is 30 cm long and 20 cm wide. Find the surface area
of the book.
FOR ONLINE READING ONLY

Solution
The book has a rectangular surface.

length = 30 cm and width 20 cm
=
Area of a rectangle = length × width

= 30 cm × 20 cm
2
= 600 cm

Therefore, the surface area of the book is 600 cm .
2

Example 3

The width of the rectangle is 40 cm. If its length is
90 centimetres, find its area.

Solution
length = 90 cm

width 40 cm

Area of a rectangle = length × width

= 90 cm × 40 cm
= 3600 cm 2

2
Therefore, the area of a rectangle is 3600 cm .

96

06/11/2024 17:17:22
MATHEMATICS STD 4 PB 2024.indd 96 06/11/2024 17:17:22
MATHEMATICS STD 4 PB 2024.indd 96