Lesson Plan
Curated OER

Geometry Practice: G.G.28 #1: Congruent Triangles

For Teachers 9th - 12th
In this congruent triangles worksheet, students solve four multiple choice problems. Students determine which statement is the appropriate reasoning to say that two triangles are congruent.
Worksheet
Curated OER

Triangle Similarity

For Students 10th
In this triangle similarity learning exercise, 10th graders solve and complete 12 different problems that include defining similar and 3 similar statements using only sides and angles. First, they determine if each pair of triangles...
Worksheet
Curated OER

Proofs with Triangles

For Students 9th - 12th
In this geometry instructional activity, students prove triangle congruence by making statements with reasons and concluding with the AAS or HL theorem. There are 2 proofs.
Worksheet
Curated OER

Geometry Practice: G.G. 28 #2: Triangle Congruence

For Students 10th - 12th
In this triangle congruence worksheet, students use SSS, ASA, AAS and HL to determine the congruence of triangles.  They identify the theorem that proves congruence.  This three-page worksheet contains 4 multi-step...
Activity
Texas Instruments

Texas Instruments: Congruent Triangles

For Teachers 9th - 10th Standards
This activity works with a PowerPoint presentation to have students answer questions as to what method a pair of triangles can be proven congruent: SSS, SAS, ASA, AAS, HL.
Unit Plan
CK-12 Foundation

Ck 12: Trigonometry: Angle Angle Side Triangles

For Students 10th - 12th
[Free Registration/Login may be required to access all resource tools.] Find the unknown side of a triangle when two angles and a side are known.
Unit Plan
CK-12 Foundation

Ck 12: Trigonometry: Law of Sines

For Students 10th - 12th Standards
[Free Registration/Login may be required to access all resource tools.] This lesson introduces the Law of Sines for two cases.
Activity
Math Is Fun

Math Is Fun: Solving Triangles

For Students 9th - 10th Standards
Find guidelines to help you "solve" triangles, which means finding the value of missing sides and angles. Provided are examples of six scenarios in which you can solve a triangle's missing measurements, as well as relevant equations,...
Handout
CK-12 Foundation

Ck 12: Geometry: Triangle Congruence Study Guide

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] Provides an overview of triangle congruence, including key terms, properties of congruent triangles, triangle postulates and theorems, and special triangles.
Website
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Congruence and Triangles

For Students 9th - 10th Standards
This site gives a very thorough explanation of how to tell if two triangles are congruent. Dr. Math explains why SSS, SAS, ASA determine that two triangles are congruent. The Dr. gives a few exercises for the reader to try then gives the...