Answer:
The figure of this problem is attached.
Givens:
- MN=PO and MO=PN.
- NO=NO by hypothesis, because both triangles have NO in common.
Now, according to the hypothesis, all three corresponding sides are congruent, that is:

Therefore, the SSS postulate, Side-Side-Side postulate, both triangles are congruent. From this congruence each corresponding pair of angles are equivalent.