In △ABC, m∠A = 63° and m∠C = 99° what is the measure of angle B
To find the measure of angle B in triangle ABC, we can use the fact that the sum of the interior angles of a triangle is always 180°.
m∠A + m∠B + m∠C = 180°
63° + m∠B + 99° = 180°
m∠B = 180° - 63° - 99°
m∠B = 18°
Therefore, the measure of angle B in triangle ABC is 18°.