BE || CD1. Given 2. ∠A ≅ ∠A2. Reflexive Property 3. ∠ACD ≅ ∠ABE3. Corresponding angles formed by parallel lines and a transversal are ≅. 4. ∠ADC ≅ ∠AEB4. Corresponding angles formed by parallel lines and a transversal are ≅. 5. ΔABE ∼ ΔACD5. AA Similarity Postulate 6. AC AB = AD AE 6. Definition of Similar Triangles 7. AC = AB + BC, AD = AE + ED7. ??? 8. AB + BC AB = AE + ED AE 8. Substitution 9. AB AB + BC AB = AE AE + ED AE 9. Addition 10. BC AB = ED AE 10. Subtraction Fill in the missing reason for the proof. A)Transitive Property B)Subtraction Property C)SSS Similarity Theorem D)Segment Addition Postulate