Question

Find the area of the polygon below is 20 square units. What is the length of the missing side?

Answer 1

6

Explanation:

The polygon showed on image is a trapezoid and to find the area of a trapezoid we use the following formula:

`(a + b)/(2) * h`

(a: base, b: base, h: height)

The first base is 4 units the second base is unknown so let x represent it, the height is also 4 units

`(4 + x)/(2) * 4 = 20`

divide both sides by 4

`(4 + x)/(2) = 5`

now multiply both sides by 2 to get rid of the fraction

4 + x = 10 subtract 4 from both sides

x = 6