The backyard of a house is in a shape of a triangle. The longest side is 10 feet shorter than twice the shortest side. The third side is 10 feet less than the longest side. If the perimeter of the yard is 81 feet what are the lengths of the sides
L = 2s - 10
T = L - 10
P = T + L + s = (2s-10)-10 + 2s-10 + s = 81
Solve for s then T and L.