Khan Academy
Khan Academy: Find Angles in Congruent Triangles
Given two triangles, determine whether they are congruent and use that to find missing angle measures. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Geometry Help
Geometry Help: Congruent Triangles
Explains the basic concept of congruent triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Cuemath
Cuemath: Congruent Triangles
Explore the world of congruent triangles in this mini-lesson. Provides a definition and examples that help with understanding their properties. Includes a short video and practice questions with answers.
Khan Academy
Khan Academy: Proofs With Transformations
Explore different ways of proving some theorems about lines and angles. Some transformations are used.
Math Open Reference
Math Open Reference: Congruent Triangles
A complete reference guide to congruent triangles. It provides definitions, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Khan Academy
Khan Academy: Find Angles in Congruent Triangles
Given two triangles, determine whether they are congruent and use that to find missing angle measures.
Khan Academy
Khan Academy: Determine Congruent Triangles
Use the triangle congruence criteria SSS, SAS, ASA, and AAS to determine that two triangles are congruent.
CK-12 Foundation
Ck 12: Interactive Geometry: 3.2 Asa and Aas Triangle Congruence
See how triangles are congruent where all corresponding angle pairs and sides are the same.
CK-12 Foundation
Ck 12: Interactive Geometry: 3.5 Applications of Congruent Triangles
Learn how two triangles are congruent if and only if their corresponding sides and corresponding angles are congruent.
CK-12 Foundation
Ck 12: Interactive Geometry: 3.4 Sss Triangle Congruence
Discover if two triangles are congruent it means that all corresponding angle pairs and all corresponding sides are congruent.
CK-12 Foundation
Ck 12: Interactive Geometry: 13.3 Sas Triangle Congruence
See how two triangles are congruent it means that all corresponding angle pairs and all corresponding sides are congruent.
Other
Nearpod: Congruent Triangles & Similarity
For this lesson on congruent triangles, students explore how to use postulates to identify if triangles are congruent by SSS, SAS, ASA, and AAS.
Other
Nearpod: Triangle Congruence
In this activity, students will prove triangles are congruent using the triangle congruence theorems.
Sophia Learning
Sophia: Corresponding Parts: Lesson 5
This lesson will define the phrase corresponding parts (e.g. angles, sides, etc.). It is 5 of 5 in the series titled "Corresponding Parts."
Sophia Learning
Sophia: Cpctc: Lesson 2
This lesson will demonstrate the use of CPCTC in triangle congruencey proofs. It is 2 of 4 in the series titled "CPCTC."
Sophia Learning
Sophia: Equilateral Triangle Interior Angles Practice Problems: Lesson 5
This lesson will provide practice problems that involve solving for unknown angle and side measures of equilateral triangles. It is 5 of 5 in the series titled "Equilateral Triangle Interior Angles Practice Problems."
Sophia Learning
Sophia: Triangle Congruence Theorem (Hl): Lesson 5
This lesson will present the Hypotenuse-Leg Triangle Congruence Theorem. It is 5 of 5 in the series titled "Triangle Congruence Theorem (HL)."
Free Math Help
Free Math Help: Congruent Triangles
Students learn about congruent triangles. The tutorial consists of definitions and sample exercises with solutions.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Congruent Triangles
Find a quick, concise explanation of Congruent Triangles. Several examples are given and clearly explained.
ClassFlow
Class Flow: Congruence in Triangles
[Free Registration/Login Required] This lesson helps teach congrence in triangles. Includes practice with postulates, theorems, and logical reasoning.
ClassFlow
Class Flow: Cpctc
[Free Registration/Login Required] This flipchart looks into the concept of CPCTC with triangles, using proofs. This flipchart has interactive parts, video, and voting.
University of Saskatchewan (Canada)
University of Saskatchewan: Triangles
This site from the University of Saskatchewan provides an explanation of similar triangles, the Pythagorean theorem, and the distance between arbitrary points in a plane. Example problems for each of these concepts are provided.
University of Cambridge
University of Cambridge: Nrich: Seven Sticks
On this one page website sharpen your logic, triangle properties, and pattern recognition skills while working on this challenge. The solution is available to double check your solution.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Congruence and Triangles
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...