jmc

Question

In parallelogram ABCD, the measure of angle ABC is 3 times the measure of angle BCD. How many degrees are in the measure of angle ADC?

Accepted Answer

FIGURE Because ABCD, we have B + C = 180^. Since B = 3 C, we have 3 C + C = 180^, so 4 C = 180^ and C = 45^. Since ADBC, we have C + D = 180^, so D = 180^ - C = 135^.