Question

Angle C is inscribed in circle O.

AB is a diameter of circle O.
What is the measure of angle B?

Answer 1

Step-by-step explanation: 19

Answer 2

The measure of m∠B = 19°.

Explanation:

Given

• Angle C is inscribed in circle O.

• m∠A = 71°

As we know that an angle inscribed in a semicircle is always a right angle.

So from the given diagram,

• m∠C = 90°

As we know that the sum of the three interior angles is equal to 180.

so

m∠A + m∠B + m∠C = 180°

71° + m∠B + 90° = 180°

m∠B = 180° - 71° - 90°

m∠B = 19°

Therefore, the measure of m∠B = 19°.