Question

A parallelogram ABCD whose angle A is ${100}^{\circ }$ .Find angle B,C,D

Answer 1

Angle A and angle B will be supplementry.
Thus
A+B = 180
100 + B = 180
B = 80 degree
Since it is a parallelogram,
A = C
B = D
Thus, A = C = 100
B = D = 80.