Question

The ratio between the perimeter and the breadth of a rectangle is 5 : 1. If the area of the rectangle is 216 sq. cm, what is the length of the rectangle?

Answer 1

it is 90 cm
let the length=5a
breadth=a
2(5a+a)=216
12a=216
a=216/12=18
thus,length=18*5=90 cm

Answer 2

Perimeter/Breadth = 5/1

2(l+b)/b = 5/1

2l+2b = 5b

3b = 2l

so b = 2/3l

Area of rectangle= 216 sqcm    l*b = 216

l*2/3l = 216

l^2 = 324

Therefore length of rectangle = 18cm