jmc

Question

The ratio of two interior angles of a parallelogram is 4:5. What is the degree measure of one of the two obtuse angles of the parallelogram?

Accepted Answer

If the measures of these two interior angles are x and y, then xy = 45 and therefore 5x=4y. We also know that x+y=180, so therefore 4x+4y=720, 9x=720, and x=80. Therefore, y = 54 80 = 100^.