Unit Plan
Cuemath

Cuemath: Median of a Triangle

For Students 9th - 10th Standards
This lesson explores the equation of the median of a triangle formula, sum of medians of a triangle, altitude of a triangle, median of equilateral triangle formula, and median of a triangle definition while discovering the interesting...
Handout
Geometry Help

Geometry Help: Congruent Triangles

For Students 9th - 10th Standards
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.
Unit Plan
CK-12 Foundation

Ck 12: Geometry: Triangle Classification Grade 8

For Students 8th
[Free Registration/Login may be required to access all resource tools.] Classifying triangles by using angle measures and side lengths.
Handout
Quia

Ixl Learning: Similar Triangles

For Students 7th - 9th Standards
Brush up on your math skills relating to similar triangles then try some practice problems to test your understanding.
Handout
Geometry Help

Geometry Help: Similar Triangles

For Students 9th - 10th Standards
Explains the basic concept of similar triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
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...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 8.g Cutting a Rectangle Into Two Congruent Triangles

For Teachers 8th Standards
This task shows the congruence of two triangles formed by cutting a rectangle in half along the diagonal. Students are asked to investigate elements of congruence and transformations among the shapes. Aligns with 8.G.A.2.
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
Math Open Reference

Math Open Reference: Triangles

For Students 9th - 10th Standards
A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.
Activity
Varsity Tutors

Varsity Tutors: Hotmath: Practice Problems: Congruent Triangles and Triangle Relationships

For Students 9th - 10th Standards
Twenty-four problems cover the topics of congruent triangles and triangle relationships in various settings. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Gpe, G Co, G Srt Unit Squares and Triangles

For Teachers 9th - 10th Standards
In this task, young scholars are shown three unit squares and two line segments connecting two pairs of vertices. They are asked to find the area of a triangle formed by intersecting lines. They can solve it using coordinate geometry or...
Interactive
Government of Alberta

Learn Alberta: Exploring Similarity and Congruence

For Students 6th - 8th Standards
Begin by watching this captivating video showing how the concepts of similarity and congruence are found in road signs. Following the video [1:27], an interactive applet allows students to resize, flip, move and rotate triangles to...
Interactive
Government of Alberta

Learn Alberta: Math Interactives: Exploring Similarity and Congruence

For Students 6th - 8th
This multimedia Learn Alberta math resource looks at how the math concepts of similarity and congruence are utilized in the making of road signs. The accompanying interactive component asks students to manipulate triangles by dragging,...
Handout
Varsity Tutors

Varsity Tutors: Hotmath: Algebra Review: Congruent Triangles

For Students 9th - 10th Standards
Find a quick, concise explanation of Congruent Triangles. Several examples are given and clearly explained.
Unit Plan
Cuemath

Cuemath: Congruent Triangles

For Students 9th - 10th Standards
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.
Unit Plan
CK-12 Foundation

Ck 12: Geometry: Sas Triangle Congruence

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] This concept introduces students to the SAS Triangle Postulate and how to prove that two triangles are congruent given only information about two pairs of sides and...
Unit Plan
CK-12 Foundation

Ck 12: Geometry: Congruent Triangles

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] This concept teaches students what it means for two triangles to be congruent and how to identify corresponding parts of congruent triangles. Students examine guided...
eBook
CK-12 Foundation

Ck 12: Interactive Geometry: 3.5 Applications of Congruent Triangles

For Students 9th - 10th Standards
Learn how two triangles are congruent if and only if their corresponding sides and corresponding angles are congruent.
Unit Plan
Sophia Learning

Sophia: Using Corresponding Parts of Congruent Triangles

For Students 9th - 10th Standards
This lesson will demonstrate the use of CPCTC in triangle congruency proofs.
Unknown Type
Khan Academy

Khan Academy: Practice: Determine Similar Triangles: Sss

For Students 8th
In this set of questions, students practice identifying side-side-side similarity among triangles. Includes hints.
Interactive
National Council of Teachers of Mathematics

Nctm: Illuminations: Making Triangles

For Students Pre-K - 1st Standards
Understand the mathematical meaning of a triangle and the idea of congruence, or sameness, in geometry.
Unknown Type
Khan Academy

Khan Academy: Solve Similar Triangles (Basic)

For Students 9th - 10th Standards
Given two similar triangles and some of their side lengths, find a missing side length. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Unknown Type
Khan Academy

Khan Academy: Solve Similar Triangles (Advanced)

For Students 9th - 10th Standards
Given two similar triangles and some of their side lengths, find a missing side length. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
eBook
CK-12 Foundation

Ck 12: Interactive Geometry: 6.7 Applications of Similar Triangles

For Students 9th - 10th Standards
Learn how similar triangles have congruent corresponding angles and proportional corresponding sides.