Answer:
See below in bold.
Explanation:
Let the length of the shortest side be x, then the longest side = 2x.
Also x + y = 2x + 1 where y = length of the middle side,
Simplifying:
2x - x - y = -1
x - y = -1 (A)
Also as the perimeter = 7:
x + 2x + y = 7
3x + y = 7 (B)
Adding (A) and (B):
4x + 0 = 6
x = 6/4 = 1.5
Plug x = 1.5 into equation B:
3(1.5) + y = 7
y = 7 - 4.5 = 2.5.
Answer:
So the shortest side = 1.5, middle = 2.5 and longest = 2*1.5 = 3.