The perimeter of a rectangular lot of land is 476 ft. This includes an easement of x feet of uniform width inside the lot on which no building can be done. If the buildable area is 133 ft by 45 ft, determine the width of the easement in feet. (Hint: visualize a bulletin board for reference)
a.) 15 ft
b.) 10 ft
c.) 25 ft
d.) 20 ft