You will build a rectangular sheep pen next to a river. There is no need to build a fence along the river, so you only need to build three sides. You have a total of feet of fence to use. Find the dimensions of the pen such that you can enclose the maximum area.
The length of the pen (parallel to the river) should be .
The width of the pen (away from the river) should be .
The maximum area of the pen is .
(Use ft for feet, and ft^2 for square feet.)

You can earn partial credit on this problem.