Answer:
9 and 15 inches
Explanation:
The unknown lengths can be found by making use of the formula for the area of a trapezoid.
__
Let x represent the shorter base. Then the longer one is (x+6), and the area is ...
A = 1/2(b1 +b2)h . . . . area of a trapezoid with bases b1, b2, and height h
72 = 1/2(x +(x+6))(6)
24 = 2x +6 . . . . . . . . . simplify, divide by 3
18 = 2x . . . . . . . . . subtract 6
9 = x . . . . . . divide by 2
15 = x+6 . . . . . . the length of the longer base
The bases are 9 inches and 15 inches in length.