Curated OER
Euclidean Proofs involving Triangles and Circles (Congruency Proofs)
In this geometry worksheet, 10th graders focus on Euclidean proofs involving triangles and circles. The eight page worksheet contains eight proofs. Solutions are not provided.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Building Two Column Proofs
Use this site to find details of how to construct a two column proof. Dr. Math responds to a question posed by a student and details the reasons for the order of steps and shows two different ways to do the same proof.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Order of a Proof
The site gives a diagram of steps to a proof. Dr. Math explains why the step order of a proof is important.
Other
Math Court: A Game of Proving Things
This site contains a game to help students better learn how to write proofs. The game has several different levels. The game can be played online or cards and board may be printed and used in the classroom.