Triangle Congruence Explorer

GOAL: The goal of this activity is for students to discover the different congruence postulates for themselves by testing different combinations of sides and angles.

INSTRUCTIONS: Click on sides and angles of the reference triangle below to select them, then hit "Test Selection" to see if your selection uniquely determines a congruent triangle.

Reference Triangle

Second Triangle

Selected elements:

Click sides or angles above

✨ Result

🤔

Select some sides and/or angles from the reference triangle, then click Test Selection to see if they uniquely determine a congruent triangle.

🏆 Discovered Postulates

Discovery awaits...

💡 Hints & Tips▼

• S stands for Side - a known length

• A stands for Angle - a known angle measure

• Try to find the minimum information needed to guarantee congruence

• Not all combinations work! Some leave room for multiple triangles

• The HL postulate only works for right triangles