The area of a trapezoid is 240cm2. The height is 20cm and the length of one of the parallel sides is 8cm. Find the length of the second parallel side. Express your answer as a simplified fraction or a decimal rounded to two places.

Answer 1

since A = (b1+b2)/2 * h, you have
(8+b)/2 * 20 = 240
so find b.