Final answer:
The AA Similarity Postulate proves that triangles AABC and ADEF are similar, based on the congruence of two angles of one triangle to two angles of another triangle.
Step-by-step explanation:
The theorem or postulate that proves that triangles AABC and ADEF are similar is the AA Similarity Postulate. This postulate states that if two angles of one triangle are congruent to two angles of another triangle, then the triangles are similar. The SSS Similarity Theorem and SAS Similarity Theorem also prove triangle similarity, but they require side length comparisons, whereas AA only requires angle comparisons which is what is given in the question's context.