Question 1015172
By inspection I can see it must be a 4' x 9' window, but we solve it by
L = W + 5
and 
A = LW = 36
(W+5)(W) = 36
W^2 + 5W - 36 = 0
(W + 9)(W - 4) = 0
W = 4 feet and then
L = W + 5 = 9 feet