Effective Arguments and Proofs

To write a proof, there must be two columns. One column states the Statements, the other column states the Reasons. When writing a proof, the Statement column says the order in which steps it takes to go from the given, to the proven. In the Reason column, this is where theorems, properties, and other steps are written to tell the meaning of the statements in the other column.There are two different types of proofs: Algebraic Proof, and Geometric Proof.

To the side, there is an example of a geometric two-column proof.