The area would be 144cm^2.
In order to find the area, we need to know the length of the rectangle. We can find that using the perimeter formula.
2l + 2w = P
2l + 2(36) = 80
2l + 72 = 80
2l = 8
l = 4
So now that we know the length is 4, we can find the area using that formula.
A = lw
A = (4)(36)
A = 144