Math question?

Question

What are the measurments of the angles of a parallelogram in which a pair of consecutive angles have measures in a ratio of 3 to 7.


A. 63°
B. 210°
C. 138°
D. 126°

Answer 1

Consecutive angles of a parallelogram are supplementary, because they are "same side interior" angles of parallel sides crossed by the one side shared by the two angles.

If their ratio is 3:7, then you know that:

3x + 7x = 180
10x = 180
x = 18

3x = 3*18 = 54
7x = 7*18 = 126

The parallelogram would have two angles that are 54 degrees, and two that are 126 degrees. (D) 126 seems to be the only matching answer.