Sophia Learning
Sophia: Types of Proofs: Lesson 3
This lesson will introduce flow chart proofs, paragraph proofs, and two-column proofs, and explain the similarity and differences between the different types of proofs. It is 3 of 5 in the series titled "Types of Proofs."
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.