A rectangle's width is one-third its length, and is perimeter is 56 feet. Find the dimensions of the rectangle. Write a mathematical translation of the situation and then saw for the dimensions
Let W = width, L = length.
We are given that W = L/3, so 3W = L.
The perimeter is 56 = W + L + W + L.
Substituting 3W for L gives W + 3W + W + 3W = 56 ⇒ 8W = 56 ⇒ W = 7, so L = 21.
The dimensions of the rectangle are 7 feet by 21 feet.