Given: L = length = 5W; P = perimeter = 2(L+W) = 12 inches Required: W = width; Formula: P=2(L+W) Solution: 12 in = 2 (L + W) 6 in = L + W 6 in = 5W + W 6 in = 6W 1 in = W Cross check: P = 2(L + W) 12 in = 2(5 in + 1 in) 12 in = 2(6 in) 12 in = 12 in