Question

A circle is centered on point B. Points A, C and D lie on its circumference.

Pro
If ZABC measures 40°, what does ADC measure?

Answer 1

m∠ADC = 20°

Explanation:

A circle B has points B, C and D on the circumference.

m∠ABC = 40° [Cntral angle]

Since measure of the central angle is double of the inscribed angle by the arc

m∠ABC = 2(m∠ADC)

Here ∠ABC = Central angle

and ∠ADC = Inscribed angle

40° = 2(m∠ADC)

m∠ADC =
`(40)/(2)`

= 20°

Therefore, measure of angle ADC is 20°.