A carpenter is building a fence around a swimming pool. One side of the pool is next to the house and does not need fencing. The carpenter has 120 feet of fencing and plans to use it all. Solve the equation w + 76 + w = 120 to find the unknown dimension of the enclosed rectangular area.
a. 12 ft
c. 20 ft
b. 22 ft
d. 18 ft