Answer:
See proof
Explanation:
 Statement Reason
1. 
 and
 and 
 bisects
 bisects 
 - Given
 - Given
2. 
 - Definition of angle bisector
 - Definition of angle bisector
3. 
 - Alternate interior angles theorem
 - Alternate interior angles theorem
4. 
 - Substitution property
 - Substitution property 
5. 
 - Vertical angles are congruent
 - Vertical angles are congruent
6. 
 - AA Similarity postulate
 - AA Similarity postulate
7. 
 - Definition of similar triangles
 - Definition of similar triangles
8. 
 - Converse of base angles theorem
 - Converse of base angles theorem
9. 
 - Substitution property
 - Substitution property