this question is particularly tough as don't know how to draw boxes and label them etc but i think it might be able to be done without seeing the boxes, here it is-

a pen is built onto an existing rectangular building where AF is 10 units and FE is 5 units. AF and FE are shared sides between the pen and the rectangular building. the perimeter ABCDE (F is the corner of the rectangular building) is 65 units. find a relationship between x and y where AB = x and DE = y

show that the area enclosed by the pen is

by completing the square, find the greatest possible area enclosed by the pen.

hats off to anyone that can do this without the visual aid