Building Intuitive Arguments for the Triangle Congruence Conditions
February 2008, Volume 101, Issue 6, Page 463
A hands-on activity that uses straws and pipe cleaners to explore and justify the triangle congruence conditions. The author uses the activities to explain when and why an idea is a postulate, theorem, accepted without need for proof, which ones need proof.
Reasoning and Proof
Similarity / Congruence