I believe you are trying to find the most Cheapest cost?
Since the area had to be 1200m^2 the most biggest numbers we could divide with is 30 x 40, which equals to 1200.
30 x 20 (expensive one the lower) = 600 (wall 3) + 20 x 20 = 1000 (wall 3 + wall 1)
40 x 13 (cheapter one the higher) = 520 (wall 4) + 32 x 13 = 936 (wall 4 + wall 2)
Add all together, $1936 to build the whole fence.
(I don't know for sure if I am right. If I am right, can I have a brainliest?)
