Angle C is inscribed in circle O.
AB is a diameter of circle O.
What is the measure of angle B?

The measure of m∠B = 19°.

Step-by-step explanation:

Given

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

So from the given diagram,

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°.

no this is a nonlinear negative