Question

In the diagram,the measure of angle ACB is 25 degrees. what is the measure of angle AOB?

Answer 1

m<AOB = 50°

Explanation:

<ACB = 25° is an inscribed angle of the circle.

<AOB is a central angle of the circle.

Thus, based on the inscribed angle theorem which states that an inscribed angle is ½ the measure of the central angle, therefore:

m<ACB = ½(m<AOB)

Substitute

25° = ½(m<AOB)

Multiply both sides by 2

2*25 = m<AOB

m<AOB = 50°