4.5 Proving Δ s are : ASA and AAS. Objectives:. Use the ASA Postulate to prove triangles congruent Use the AAS Theorem to prove triangles congruent.
Given: A D, C F, BC EF
Prove: ∆ABC ∆DEF
You are given that two angles of ∆ABC are congruent to two angles of ∆DEF. By the Third Angles Theorem, the third angles are also congruent. That is, B E. Notice that BC is the side included between B and C, and EF is the side included between E and F. You can apply the ASA Congruence Postulate to conclude that ∆ABC ∆DEF.
Is it possible to prove these triangles are congruent? If so, state the postulate or theorem you would use. Explain your reasoning.