96
Perimeter of square:
4(x+15) = 4x + 60
Perimeter of triangle:
5x + 5x + x - 3 = 11x -3
Since they are the same set equal to each other and solve for x
4x + 60 = 11x - 3
63 = 7x
9 = x
Replace in equation for triangle perimeter:
11(9) -3 = 99 - 3 = 96
