In the above figure ∠ AOB =80°. What dose
∠ ACB equal?
A. 40
B. 80
C. 10
D. 160

Answer:
Find out the what does ∠ ACB equal .
To prove
As given
∠ AOB =80°
By using the relationship between the inscribed angle and central angle.
[tex]Inscribed\ angle = \frac{1\times central\ angle}{2}[/tex]
Here
Inscribed angle = ∠ACB
Central angle = ∠AOB = 80°
[tex]\angle ACB = \frac{80}{2}[/tex]
∠ACB = 40°
Option (A) is correct .