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: 13.3 Sas Triangle Congruence
See how two triangles are congruent it means that all corresponding angle pairs and all corresponding sides are congruent.
Homeschool Math
Homeschool Math: Introduction to Sine
This is an introductory lesson plan about the trigonometric function sine. Young scholars will study several similar right triangles and the ratio of certain two sides in them.
PBS
Pbs Learning Media: Triangles: Targeted Math Instruction
Students will learn how to apply the properties and characteristics of all triangles to solve real-world problems and identify and use the unique characteristics of right, isosceles, equilateral, acute, obtuse, and scalene triangles.
Quia
Ixl Learning: Similar Triangles
Brush up on your math skills relating to similar triangles then try some practice problems to test your understanding.
Khan Academy
Khan Academy: Triangle Similarity Review
Review the triangle similarity criteria and use them to determine similar triangles.
Khan Academy
Khan Academy: Right Triangle Word Problems
Solve word problems by modeling real-world (and not-so-real) situations as right triangles and using trigonometry.
Other
Nearpod: Congruent Triangles & Similarity
In this lesson on congruent triangles, students explore how to use postulates to identify if triangles are congruent by SSS, SAS, ASA, and AAS.
Ministry of Education and Employment of Spain
Red Escolar: Un Triangulo Sorprendente
In Spanish. Different activities which involve the following concepts: right triangles, perpendicular lines, classification of triangles, area of a square and Pythagorean theorem.
AAA Math
Aaa Math: Finding the Third Angle of a Triangle
Finding the third angle of a triangle becomes easier by the explanation and examples presented.
Other
Mathematics Internet Library: Free Internet Books
Practice problem worksheets are available for students needing to study basic terms relating to triangles and other math concepts.
Sophia Learning
Sophia: Using Right Triangle Trigonometry to Find the Area of Regular Polygons
This lesson will demonstrate how to use right triangle trigonometry and special right triangles (45-45-90 and 30-60-90) to find the area of triangles given the side lengths of the polygon. It is 2 of 4 in the series titled "Using Right...
Sophia Learning
Sophia: Using Similar Triangles to Make Indirect Measurements
This lesson explains why similar triangles can be used to make indirect measurements, and provides an example.
ClassFlow
Class Flow: The Law of Cosines
[Free Registration/Login Required] This flipchart defines and uses the law of cosines to find the missing sides and angles of oblique triangles.
ClassFlow
Class Flow: Triangle Segments
[Free Registration/Login Required] In this flipchart, students use the interactive features of Activstudio to understand how to use the properties of perpendicular bisectors, angle bisectors, medians and altitudes of a triangle.
ClassFlow
Class Flow: Triangles and Angles
[Free Registration/Login Required] Classify angles by their side and angles. Find angles and measure in triangles.
ClassFlow
Class Flow: Trigonometry
[Free Registration/Login Required] Students explore trigonometric functions using the interactive features of Activstudio. Students apply their understanding of trigonometric sense to determine the side lengths and angles of various...
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.
ClassFlow
Class Flow: Basic Right Triangle Trigonometry
[Free Registration/Login Required] This flipchart shows the basic relationships between trig functions and the sides and angles of a right triangle.
ClassFlow
Class Flow: Congruency
[Free Registration/Login Required] Here are many variations of congruent triangles displayed for students to test their knowledge.