A.) 60°
B.) 64°
C.) 45°
Angle B is 64° because the angle in front of it is also 64°. They carry the same measurement because they are alternate interior angles.
You can find C by computing the measurement of the rest of the triangle, 64+71 which is 135. Since a triangle has a complete measure of 180° you subtract 135 from 180, leaving you 45°.
And you can find A in the same manner you found c, by computing the rest of the triangle and subtracting it from 180°, 180- 120 = 60.
