Question: A farmer plans to use 180 feet of fencing to enclose a rectangular region, using part of a straight river bank instead of fencing as one side of the rectangle
(a) Find the area A of the region if the length of the side parallel to the river bank is four times the length of an adjacent side.
(b) Find the area A of the region if the length of the side parallel to the river bank is one-fourth the length of an adjacent side.
(c) Find the area A of the region if the length of the side parallel to the river bank is the same as the length of an adjacent side.