1: Write "equal to vertex angle" as "if. Then." form 2: is there an inverse theorem for theorem "equal to vertex angle"? No counterexample is given

1: Write "equal to vertex angle" as "if. Then." form 2: is there an inverse theorem for theorem "equal to vertex angle"? No counterexample is given

1. If two angles are opposite to each other, they are equal
2. There is no inverse theorem. If two angles are 45 degrees, then they are equal