Respuesta :

Answer:

is it from a text book

Step-by-step explanation:

Let L = length, W = width and P =Perimeter

L = 3W

and

P + 2(L + W) = 120

L + W = 60

Substitute

3W + W = 60

4W=60

W=60/4

W=15

L+W=60

L+15=60

L=60-15

L=45