Kevin 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 Kevin has 850 feet of fencing, what dimensions would maximize the area of the pen?a) Let ? be the length of the pen perpendicular to the barn. Write an equation to model the area of the pen in terms of ?.Area = ______________b) What width ? would maximize the area?? = ______________