Question

The area of a trapezoid is 243 cm² the height is 18 cm and the length of one of the parallel sides is 10 cm find the length of the second parallel side

Answer 1

Given:

Area of trapezoid is, A = 243 cm².

The height of the trapezoid is, h = 18 cm.

One parallel side of the trapezoid is, a = 10 cm.

The objective is to find the second parallel side is, b.

The formula to find the area of the trapezoid is,

$A=\frac{1}{2}\times h\times(a+b)$

Now substitute the given values in the above formula to find the second parallel side b.

$\begin{gathered} 243=\frac{1}{2}\times18\times(10+b) \\ 10+b=\frac{243\times2}{18} \\ 10+b=27 \\ b=27-10 \\ b=17\text{ cm} \end{gathered}$

Hence, the length of the second parallel side is, b is 17 cm.