## Elementary Geometry for College Students (6th Edition)

40 $ft^{2}$
The area of a trapezoid whose bases have lengths b1 and b2 and altitude has length of h is given by A = $\frac{1}{2}$*h(b1+b2) Lets take b1 = BC = 13ft b2 =AD = 7ft h = 4 ft Therefore A = $\frac{1}{2}$*4* (13+7) = 2*(20) = 40 $ft^{2}$