1. The problem is to understand how to name congruent triangles. 2. Congruent triangles are triangles that have exactly the same size and shape. 3. To name congruent triangles, we use the correspondence of their vertices. For example, if triangle ABC is congruent to triangle DEF, then vertex A corresponds to vertex D, B to E, and C to F. 4. The order of letters in the triangle name is important because it shows which vertices correspond to each other. 5. If \( \triangle ABC \cong \triangle DEF \), then side AB corresponds to side DE, BC corresponds to EF, and AC corresponds to DF. 6. This naming helps us understand which parts of the triangles are equal when proving congruence using criteria like SSS, SAS, ASA, AAS, or HL. 7. Remember, always match the vertices in the same order to correctly name congruent triangles.