Answer:
1. Given
2. definition of vertical angles
3. SAS triangle similarity theorem
Step-by-step explanation:
1. Given simply means the problem directly tells you it is true
2. Vertical angles are angles that share 2 lines and are congruent.
3. SAS triangle similarity theorem is the theorem that proves 2 triangles with a similar side, angle, and side (in that order) are similar.
