SOLUTION: i need help with this question, if two angles are opposite angles of a parallelogram are they congruent?

Question 172808: i need help with this question, if two angles are opposite angles of a parallelogram are they congruent?
Answer by colliefan(242) (Show Source): You can put this solution on YOUR website!
Draw a parallelogram and look at the opposite angles in the upper left and lower right of the parallelogram. Extend the sides of the parallelogram that run horizontally so they extend beyond the parallelogram. You can see that the opposite angles are now equal because the alternate interior angle to the angle in the upper left is the complementary angle to the one in the lower right of the parallelogram and they must all be equal.

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