Explain why you need to prove 2 triangles congruent before you can prove the parts of the triangles congruent. (2 points)
You need to prove two triangles congruent before you can prove the parts of the triangles congruent because congruent triangles have corresponding parts that are equal. When two triangles are congruent, it means that all corresponding sides and angles are congruent.
Once you have established that the triangles are congruent, you can rely on the fact that corresponding parts are equal to prove that specific parts of the triangles are congruent. If you attempt to prove the parts of the triangles congruent without proving the triangles congruent, you cannot guarantee that the parts have the same measurements.
Therefore, proving the congruence of the entire triangles is necessary to establish the congruence of the individual parts within them.