Read the proof. Given: AB ∥ DE Prove: △ABC ~ △EDC Triangles A B C and E D C connect at point C. Sides A B and D E are parallel. Statement Reason 1. AB ∥ DE 1. given 2. ∠ACB and ∠ECD are vert. ∠s 2. definition of vertical angles 3. ∠ACB ≅ ∠DCE 3. vertical angles are congruent 4. ∠BDE and ∠DBA are alt. int. ∠s 4. definition of alternate interior angles 5. ∠BDE ≅ ∠DBA 5. alternate interior angles are congruent 6. △ABC ~ △EDC 6. ? AA similarity theorem ASA similarity theorem AAS similarity theorem SAS similarity theorem