Question

In parallelogram a b c d, measure of angle a d c equals 60 degrees. what is measure of angle d c b? ________degree

Answer 1

The measure of angle dcb is 120°.
Because in a parallelogram, Consecutive angles are supplementary that means (D + C = 180°).
given that angle adc is equal to 60°
So, ∠adc + ∠dcb = 180°
60 ° + ∠dcb = 180°
∠dcb = 180 - 60 = 120°
Thus, the measure of angle dcb is 120°.