Skip to content

Transversal Angle Explorer

Run Fullscreen

About This MicroSim

This interactive tool lets you explore the four types of angle relationships formed when a transversal crosses two parallel lines. Drag the red handle to rotate the transversal and watch all eight angles update in real time. Click the color-coded buttons to highlight each relationship type and see the equations that prove the relationship holds for any transversal angle.

How to Use

  1. Drag the red handle to rotate the transversal and change all eight angle measures
  2. Click a relationship button to highlight the relevant angle pairs with color-coded arcs
  3. Read the info panel (lower-left) to see the equations and property for each relationship
  4. Click Reset to clear all highlighting
  5. Observe that the relationships hold no matter how you tilt the transversal

Angle Relationships

Relationship Pairs Property
Corresponding 1 & 5, 2 & 6, 3 & 7, 4 & 8 Congruent
Alt. Interior 3 & 6, 4 & 5 Congruent
Alt. Exterior 1 & 8, 2 & 7 Congruent
Same-Side Interior 3 & 5, 4 & 6 Supplementary (180)

Key Insight

When parallel lines are cut by a transversal:

  • Three relationship types produce congruent (equal) angle pairs
  • One relationship type produces supplementary (sum to 180) angle pairs
  • These properties hold for every transversal angle

Learning Objectives

  • Identify the four angle relationship types formed by parallel lines and a transversal
  • Verify that corresponding, alternate interior, and alternate exterior angles are congruent
  • Verify that same-side interior angles are supplementary
  • Evaluate how all relationships hold as the transversal angle changes

Bloom's Taxonomy Level

Analyzing and Evaluating - Identifying angle relationships and verifying their properties through interactive exploration.

Iframe Embed Code

<iframe src="https://dmccreary.github.io/geometry-course/sims/transversal-angle-explorer/main.html"
        height="652px"
        width="100%"
        scrolling="no"></iframe>