The sides of a triangle are in the ratio of 1: 2: 2 and the perimeter of the triangle is 15 feet. the length of the shortest side is
2.5 feet
3 feet
5 feet
7.5 feet

We let x be the multiple of each side of the triangle. Then, we add all sides to obtain the perimeter.

1x + 2x + 2x = 15
5x = 15
x = 15/5
x = 3

The multiple is 3. We multiply this to the ratio to get the actual lengths of the sides. That would be 3, 6 and 6. Thus, the shortest side is 3 feet.