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Two-Column Proof Builder

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About This MicroSim

This interactive tool guides students through constructing a complete two-column proof for the Vertical Angles Theorem. Instead of typing, students click on empty cells and select the correct statement or reason from popup options.

Given: ∠1 and ∠2 are vertical angles

Prove: ∠1 ≅ ∠2

How to Use

  1. Click on any empty cell in the proof table
  2. Select the correct statement or reason from the popup menu
  3. Green checkmarks (✓) indicate correct answers
  4. Red X marks (✗) indicate incorrect answers
  5. Use Hint to automatically fill in the next correct cell
  6. Use Check Proof to verify all answers
  7. Use Reset to start over

Interactive Features

  • Click-to-fill interface - No typing required
  • Immediate feedback - See if each answer is correct
  • Progress tracking - Track how many cells are filled correctly
  • Hint system - Get help when stuck
  • Scrambled options - Options are randomized each time

The Proof Structure

The proof uses 9 logical steps:

  1. Start with the given information
  2. Identify linear pairs
  3. Apply the Linear Pair Postulate
  4. Use the definition of supplementary
  5. Apply algebraic properties
  6. Conclude with angle congruence

Learning Objectives

  • Apply the structure of two-column proofs
  • Connect statements with appropriate reasons
  • Understand the logical flow of geometric proofs
  • Practice the Vertical Angles Theorem proof

Bloom's Taxonomy Level

Applying - Constructing proofs by selecting correct components.

Iframe Embed Code

<iframe src="https://dmccreary.github.io/geometry-course/sims/two-column-proof-builder/main.html"
        height="652px"
        width="100%"
        scrolling="no"></iframe>

References

  1. Two-Column Proofs - Khan Academy
  2. Vertical Angles Theorem - Wolfram MathWorld