Question

The perimeter of a rectangle is 40cm If the length of rectangle is thrice the breadth. Then find it's area​

Answer 1

Step-by-step explanation:

Perimeter of rectangle= 2(length + breadth)

2( l+b) = 40

Length of rectangle= thrice the breadth

l = 3b

putting value of l in 2(l+b)= 40

2(3b+b) = 40

2(4b) = 40

8b = 40

b = 40/8

b = 5

put value of b in l= 3b

l = 3× 5

l = 15

So length of rectangle is 15 cm and breadth is 5 cm.

So the area = length× breadth

area = 15× 5

= 75 cm