Answer:
3.5 ft.
Step-by-step explanation:
Let the x ft be the length of the smallest piece then the longest piece will be x+2.5 ft and the middle piece is x + 2.5 - 2 = x + 0.5 ft.
So we have:
x + x + 2.5 + x + 0.5 = 12
3x + 3 = 12
3x = 9
x = 3.
So the length of the middle-sized piece is 3 + 0.5
= 3.5 ft.