Question

The height of a trapezoid is 13 inches, one of the bases measures 22 inches. If the area of the trapezoid is 318.5 square inches, find the length of the other base.
2.5 inches


71 inches


34.25 inches


27 inches

Answer 1

$A = \dfrac{(B + b)h}{2}$

$318.5~in^2 = \dfrac{(22~in + b) \times 13~in}{2}$

$637~in^2 = 13~in(22~in +b)$

$637~in^2 = 286~in^2 + (13~in)b$

$351~in^2 = (13~in)b$

$b = \dfrac{351~in^2}{13~in}$

$b = 27~in$

Answer: The answer of the other base is 27 inches. Choice D.