Let the side of the rectangle where the semicircle track is built be 2x, and the other dimension of rectangle be y. What is the perimeter of the track in terms of x,y? The perimeter is the constraint as the track is 440 yards long. Use that to express y in terms of x.

Then, what is the area of the pool? This should be a function in x only. Make sure to write out the domain of this function. It will help in answering parts (b) and (c).

Proceed with differentiation to find critical point(s), and determine the maximum area.