Question

The rectangle shown here is made up of identical squares. If the perimeter of the rectangle is 18 cm, what will be its area(in sq. cm)?

• A. 20

Answer 1

The correct option is A 20
Number of squares along the length of the rectangle = 5
So, length of rectangle = 5 $\times$ side of square
Number of squares along the breadth of the rectangle = 4
So, breadth of rectangle = 4 $\times$ side of square
So, half of the perimeter of the rectangle
= 5 $\times$ side of square + 4 $\times$ side of square
= 9 $\times$ side of square
It means the perimeter of the rectangle will be 18 $\times$ side of square.
So, 18 cm = 18 $\times$ side of square
It means the side of each square is 1 cm.
So, the area of each square = 1 $\times$ 1 = 1 sq. cm
Number of squares in the rectangle = 20
So, the area of the rectangle = 20 $\times$ 1
= 20 sq. cm