Perimeter Word Problem

Question

The longest side of a triangle is twice the length of the shortest side. The third side is 12 inches shorter than the longer side. Find the length of the sides of the triangle if the perimeter is 78 inches.

Answer 1

shortest side is x

longest side is 2x

3rd side is 2x-12

x+2x+2x-12 = 78

5x-12 = 78

5x = 90

x = 18

shortest side is 18

longest side is 36

3rd side is 24