The measure of arc QS is (4x - 18)°. What is the value of x?

40.5, 49.5, 94.5, 180

Solution:

Given: Measure of arc QS = (4x - 18)°

Arc QS is a semicircle and the angle subtended by the semicircle at the centre is 90°

Let us use this to determine the value of x

4x - 18 = 90°

First add 18 on both sides

4x - 18 + 18 = 90 + 18

4x = 108

Divide both sides by 4

x = 108/4

x = 27

Therefore, the value of x is 27

The measure of arc QS is (4x - 18)°. What is the value of x? 

Summary:

If the measure of arc QS is (4x - 18)° then the value of x is 27