In a parallelogram ABCD if angle A is 60o then the measure of angle B is:
120o
60o
30o
90o
Sum of adjacent angles of a parallelogram is 180o.
∠A + ∠B = 180°
∠B = 180° - 60° = 120°
In the adjoining figure, A, B, and C are three points on a circle O. If angle AOB = 90° and angle BOC = 120°, then angle ABC is:
Measure of the four angles ∠A, ∠B, ∠C and ∠D in the given parallelogram will be