Please help, it's much appreciated! <3333 It's midterms studying. 20 points!

A manufacturer makes trusses, or triangular supports, for the roofs of houses. Each truss is the shape of an isosceles triangle in which the sides are congruent. The length of the base is 4/3 the length of the congruent sides.

The perimeter of each truss is 60ft. Find each side length