Solve the Following.

a. A rectangular pen is built with one side against a barn. If 2400 m of fencing are used for the other three sides of the pen, what dimensions maximize the area of the pen? b. A rancher plans to make four identical and adjacent rectangular pens against a barn, each with an area of 25 m (see figure). What are the dimensions of each pen that Bar minimize the amount of fence that must be used? 25 25 25 25