Question

Prove that the opposite angles of a parallelogram are congruent.

Answer 1

@RyanL. think you can help me???

Answer 2

I hate math but I would say that all the sides are the same. Don't take my word for it but that's what I think.

Answer 3

We know that if two lines intersect at a point then opposite angles will be the same (in the diagram, a and a' are equal etc).
If you extend the lines of the parallelogram you will see 4 sets of these angles. Use the laws of parallel lines to complete the proof.