Question

Question 12 the length of a rectangle is three times its width. if the perimeter of the rectangle is 40 m , find its area.

Answer 1

Let the width be x.

Length = 3x

Perimeter = 40

2*(L + W) = 40

L + W = 20

3x + x = 20

4x = 20

x = 5

Hence,

Length = 15 m

Width = 5 m

Area = L*W = 15 * 5 = 75 sq. m

Answer 2

The area of the rectangle is 75 squared meters.

Explanation:

Width of the rectangle = w

Length of the rectangle = l = 3w

Perimeter of the rectangle = P = 40 m

Perimeter of the rectangle = 2(l+w)

`2(l+w)=40 m`

`2(3w+w)=40 m`

`8w=40 m`

`w=(40 m)/(8)=5 m`

`l=3w=3* 5 m=15 m`

The area of the rectangle ,A= l × w

`A = 5 m* 15 m = 75 m^2`

The area of the rectangle is 75 squared meters.