Question

find the perimeter of a rectangle having area equal to 144cm2 and sides in the ratio 4:9

Answer 1

let the ratio be 4x 9x
144cm2 =4x*9x
144=36x
X=144/36
X=4
4x=4*4=16
9x=9*4=36
perimeter=2(16+36)
2*52
104cm

Answer 2

Length * breadth = 144

Also length :breadth = 4:9

Length = 4x

Breadth = 9 x

4x * 9x = 144

36 x^2 = 144

x= √(144÷36) = 2

Length = 4x = 4* 2 = 8

Breadth = 9 x = 9 *2 = 18

Perimeter = 2(length+ breadth)

= 2(18+8) = 52