Answer:

1. definition of linear pair

2.subtitution property

3. given

4. alternate interior angles are congruent

5. given

6. definition of midpoint

7. vertical angles are congruent

8. ASA

9. CPCTC

1. SAS(side-angle-side) congruence postulate

ASA(angle-side-angle)Congruence postulate

SSS(side-side-side)Congruence postulate

SAA(side-angle-angle)Congruence postulate

2. statement-a sentence which has objective and logical congruent

postulate-a statement which is accepted true without validity or proof

axiom- a statement that is taken to be true

theorem-a true statement that needs to be proven

3. Yes