1. AB ≅ CD
1. given
2. ∠ABE and ∠CDE are right angles
2. given
3. ∠ABE ≅ ∠CDE
3. all right angles are ≅
4. ∠AEB and ∠CED are vertical angles
4. definition of vertical angles
5. ∠AEB ≅ ∠CED
5. vertical angles theorem
6. △ABE ≅ △CDE
6. ♣
7. AE ≅ CE
7. CPCTC