Triangle Forge
Triangle Congruence and Similarity Lab (SSS, SAS, ASA, AAS, HL)
Students forge copies of broken shards by choosing the three measurements that pin a triangle down — and see for themselves why SSA and AAA fail.
- Grades
- Grade 8 and Math 2
- Math
- Triangle congruence and similarity
- Format
- Solo
- Time
- One class period
- Runs on
- Any browser — Chromebooks and projectors
How the lab plays
- Every measurement costs coal, so students look for the cheapest proof.
- They inspect marked pairs, including shared sides and vertical angles.
- Then they fill orders for similar triangles.
Skills covered
- Triangle congruence criteria: SSS, SAS, ASA, AAS and HL
- Why SSA and AAA don't guarantee congruence
- Similar triangles
Built-in questions follow the NC Standard Course of Study. You can upload your own question banks for any state's standards.
How to run it
Introduce it
Use the slide deck from the lab's resource shelf to set up the investigation.
Work the missions
Students sign in with their login cards and work through the missions, measuring and recording as they go.
Review the data
Every student's data is saved. View it in the Teacher Portal or download it as a CSV.
Discuss and check
Bring the class together around the results, then finish with the exit ticket.
Try Triangle Forge with your class
Triangle Forge is one of 19 games and labs in Numeria. A free trial unlocks all of them, plus the Teacher Portal, login cards, one class leaderboard, and the slides, guides and activities that come with every lab.
Up to 6 class periods, 40 students each. Each request is approved by hand, usually within a day.
Questions? justinowens@justinowensauthor.com
