Question 13 1 pt 119 Details Zachary wants to build a rectangular pen for his animals. One side of the pen will be against the barn; the other three sides will be enclosed with wire fencing. If Zachary has 400 feet of fencing, what dimensions would maximize the area of the pen? a) Let w be the length of the pen perpendicular to the barn. Write an equation to model the area of the pen in terms of w Area= b) What width w would maximize the area? W=>