A farmer is building a fence to enclose a rectangular area against an existing wall, shown in the figure below.

A rectangle labeled, Fenced in Region, is adjacent to a rectangle representing a wall.
A rectangle labeled, Fenced in Region, is adjacent to a rectangle representing a wall.
Three of the sides will require fencing and the fourth wall already exists.

If the farmer has 164 feet of fencing, what is the largest area the farmer can enclose?