CK-12 Foundation
Ck 12: Geometry: Sss Similarity
[Free Registration/Login may be required to access all resource tools.] This concept teaches students to decide whether or not two triangles are similar using SSS Similarity.
Alabama Learning Exchange
Alex: A Triangle to Remember
This lesson will introduce students to different types of triangles by using a clip from the movie A Walk to Remember. They will take part in interactive tutorials to strengthen the concepts of classifying triangles. The students will...
Alabama Learning Exchange
Alex: Card Table Project
Students will work in groups to design a card table. Students will communicate with each other through a class blog or class discussion page. Students will then work in groups to design a card table. After the design phase, students will...
Alabama Learning Exchange
Alex: Geometric Mean and Indirect Measurement
In this inquiry-based lesson, students will work in groups to gather measurements needed to approximate the height of a building. Students will discover how geometric mean can be used to find the lengths of missing sides of right...
Math Open Reference
Math Open Reference: Obtuse Triangle
A reference guide to obtuse triangles. It provides a definition and interactive animated activity that enhances further explanation.
Math Open Reference
Math Open Reference: Acute Triangle
Explore acute triangles with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.
Geometry Help
Geometry Help: Similar Triangles
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.
Geometry Help
Geometry Help: Right Triangles
Explains the basic concept of right triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Geometry Help
Geometry Help: Isosceles Triangles
Explains the basic concept of isosceles triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Geometry Help
Geometry Help: Equilateral Triangles
Explains the basic concept of equilateral triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
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.
Math Open Reference
Math Open Reference: Area of an Equilateral Triangle
Learn about the area of an equilateral triangle with this helpful reference tool. Provides a detailed definition, examples, and an internet activity that enhances further explanation. Includes links to related topics.
Quia
Ixl Learning: Types of Triangles
Brush up on your math skills relating to the types of triangles then try some practice problems to test your understanding.
Quia
Ixl Learning: Similar Triangles
Brush up on your math skills relating to similar triangles then try some practice problems to test your understanding.
E-learning for Kids
E Learning for Kids: Math: Riksjas, Toek Toek: Polygons
Explore polygons with Wang, a ricksha puller. Answer his questions and he will give you a free ride!
E-learning for Kids
E Learning for Kids: Math: Dojo: Polygons and Time Zones
Students will play several learning games to explore polygons such as triangles, and how to determine the area of triangles and the different types of triangles. They will also explore time zones.
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: Scalene, Isosceles, and Equilateral Triangles: Lesson 1
This lesson will define scalene, isosceles, and equilateral triangles. It is 1 of 5 in the series titled "Scalene, Isosceles, and Equilateral Triangles."
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.
Math Is Fun
Math Is Fun: Triangles
Students learn about the terminology and formulas associated with triangles. The learning resource consists of definitions, diagrams, and examples.
Shmoop University
Shmoop: Basic Geometry: Triangles
The geometry resource explores triangles. Descriptions, examples, and practice exercises are included.
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.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Types of Triangles
Find a quick, concise explanation of the different types of triangles. Examples are given and clearly explained.
National Council of Teachers of Mathematics
Nctm: Illuminations: Triangle Classification
Use this applet to show how the placement of the third vertex of a triangle affects the classification of that triangle.