Unit 1 · Logic and Proof

1.8Proof Formats

Quick Answer

The same proof can be written in three formats: two-column (most common in geometry), paragraph (written in sentences), and flow-chart (boxes connected by arrows). All three must include the same logical steps and reasons.

Essential Question

How do two-column, paragraph, and flow-chart proofs differ in format while conveying the same logical argument?

Learning Goals

  • 1Write a proof in two-column format.
  • 2Convert a two-column proof to paragraph form.
  • 3Represent a proof as a flow chart.
  • 4Identify the advantages of each proof format.

Key Vocabulary

Paragraph proof

A proof written in complete sentences that explains each logical step.

Flow-chart proof

A proof represented as a diagram with boxes (statements) connected by arrows (logical flow) and reasons written below each box.

Full lesson content coming soon

Worked examples, guided practice problems, a workbook, quiz, and downloadable PDF resources will be added to this lesson in Phase 2. The learning goals and vocabulary above reflect the complete lesson scope.