In this case, one side is equal to x, and the other, 7x. Knowing this, you can make the equation 7x + x = 32. Now solve for x.
To solve for x:
Add like terms.
8x = 32.
Divide both sides by 8.
x = 4.
So the short side is 4, and since x = 4, the long side is 28.
28+4=32.
I hope this helped you!