Given: ΔABC and ΔDEF, where ∠A ≅ ∠D and ∠B ≅ ∠E Prove: ΔABC ~ ΔDEF Transitive property of congruence Transitive property of equality Transitive property of similarity A'B' & DE lie in the same direction. A'C' & DF lie in the same direction. Commutative property of similarity A''B'' = DE, A''C'' = DF, B''C'' = EF A'B' = DE, A'C' = DF, B'C' = EF A'B' & DE lie in the same direction. B'C' & DF lie in the same direction.