Question

The area of a trapezoid is

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

Answer 1

The answer is 15cm

Explanation:

Let b be the length of the second parallel side

Area of a trapezium is given by

`A = (1)/(2) (a + b)h`

where

h is the height

a and b are the parallel sides

From the question

Area = 230 cm²

height = 20cm

one of parallel side / a = 8 cm

Substitute the values into the above formula and solve for b

That's

`230 = (1)/(2) ( 8 + b) 20`

Reduce the fraction with 2

That's

`230 = (8 + b) * 10`

Expand the terms

That's

`230 = 80 + 10b`

`10b = 230 - 80 \\ 10b = 150`

Divide both sides by 10

We have the final answer as

b = 15cm

Hope this helps you