One side of a triangle is one-third the longest side. The third side is 13 feet less than the longest side. The perimeter is 85. Find all three sides.
Let the longest side = L
So one side = (1/3)L and the other = L -13
So
L + (1/3)L + L -13 = 85
(2 + 1/3)L = 85 + 13
(7/3)L = 98
L = 98 ( 3/7) = (98 / 7) * 3 = 14* 3 = 42
(1/3)L = 14
L = 13 = 29