Question

The area of a trapezoid is 243cm2. The height is 18cm and the length of one of the parallel sides is 10cm. Find the length of the second parallel side. Express your answer as a simplified fraction or a decimal rounded to two places.

Answer 1

`Side_2 = 17\ cm`

Explanation:

Given

Shape: Trapezoid

`Area = 243cm^2`

`Height = 18cm`

`Side_1 = 10cm`

Required

Determine the length of the second parallel side

The area of a trapezoid is:

`Area = (1)/(2)(Side_1 + Side_2) * Height`

Substitute values for Area, Height and Side1

`243 = (1)/(2)(10 + Side_2) * 18`

Multiply both sides by 2

`2 * 243 = 2 * (1)/(2)(10 + Side_2) * 18`

`486 = (10 + Side_2) * 18`

Divide both sides by 18

`27 = 10 + Side_2`

`Side_2 = 27 - 10`

`Side_2 = 17\ cm`

Hence;

The length of the second parallel side is 17cm