Question

The area of a trapezoid is 132 cm 2. The height is 12cm and the length of one of the parallel sides is 9cm. Find the length of the second parallel side. Express your answer as a simplified fraction or a decimal rounded to two places.

Answer 1

Answer

Find out the length of the second parallel side.

To prove

Formula

$Area\ of\ Trapezoid = \frac{(a + b)\times h}{2}$

Where a , b are the parallel sides of trapezoid and h is the height of the trapezoid.

As given

The area of a trapezoid is 132 cm².

The height is 12cm and the length of one of the parallel sides is 9cm.

Here h = 12cm

         a = 9cm

Put in the formula

$132= \frac{(9 + b)\times 12}{2}$

132 × 2 = 9 × 12 + 12b

264 = 108 + 12b

264 - 108 = 12b

156 = 12b

$b = \frac{156}{12}$

b = 13cm

Therefore the  length of the second parallel side is 13cm.