The sides of a rectangle are in a 3 : 4 ratio. What is the length of the shorter sides of the rectangle if its perimeter is 42 cm?

Respuesta :

P = 2(L+W)
so
42/2 = 21
 
21 /  7= 3

3 x 3 = 9
3 x 4 = 12

answer

the length of the shorter side is 9