Need help with my math

Question

One side of a triangle is one third the longest side.the third side is 8 feet less than the longest side.the perimeter is 104.find all three sides

Answer 1

S=L/3

T=L-8

P=S+T+L = 104

104 = L/3 + L-8 + L

7L/3 = 112

L = (3/7)112 = 3(16) = 48 ft

S = 48/3 = 16 ft

T = 48-8 = 40 ft

triangle is 40x48x16 ft