Question

The length of a rectangle is five times its width. if the area of the rectangle is 405 yd2 , find its perimeter.

Answer 1

L = 5W
A = LW = 405

plug in 5W FOR L 
A = LW
A = (5W)W = 405
5W^2 = 405
W^2 = 405/5
W^2 = 81
Take the squareroot
w = 9

L = 5W
We now know W = 9
L=5(9)
L =45

P=2(L+W)
P =2(45 + 9)
P =108