A trapezoid has a height of 6 inches, a base length of 9 inches, and an area of 72 square inches. What is the length of the other base?
Areatrapezoid = (1/2) height * (sum of base lengths)
So we have
72 =(1/2) (6) ( 9 + B) where B is the unknown base lenght....simplify
72 = 3 ( 9 + B) divide both sides by 3
24 = 9 + B subtract 9 from both sides
15 = B = the length of the other base