CK-12 Foundation
Ck 12: Elem Math: Determining the Length of an Unknown Side of a Triangle
[Free Registration/Login may be required to access all resource tools.] Students watch a video tutorial and attempt practice problems on how to determine the unknown side length of a triangle.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.4 Triangles
Explore and measure a variety of triangles.
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.
Math Is Fun
Math Is Fun: Interactive Triangles
This is an excellent tool for students to explore how changes in the size of a triangle's sides or angles affect its appearance. Different types of triangles and angles are presented.
Math Open Reference
Math Open Reference: Triangle Quiz
Students are assessed on different types of triangles. Definitions of the triangles are included.
McGraw Hill
Glencoe Mathematics: Online Study Tools: Triangles and Angles
This site gives a short interactive quiz which allows students to self-assess their understanding of the concept of triangles and angles.
AAA Math
Aaa Math: Types of Triangles Based on Sides
Students can practice classifying triangles based on side lengths through a series of self-check exercises and timed learning games.
Math Open Reference
Math Open Reference: Triangles
A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.
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...
National Council of Teachers of Mathematics
The Math Forum: Problems Library Geometry Triangles
This site contains a wealth of problems that deal with the basic definitions of medians, altitudes, angle bisectors, and perpendicular bisectors or the defining characteristics of the different types of triangles. There are also...
Merriam-Webster
Merriam Webster: Dictionary Illustration: Types of Triangles
A labeled illustration of six different types of triangles.
Other
Ic Teachers: Shapes: Triangles
Are you looking for a very basic website that will explain the basic properties of a triangle? Use this site to learn about the properties of equilateral triangles, isosceles triangles, right triangles,and scalene triangles. There are...
Wolfram Research
Wolfram Mathworld: Isosceles Triangle
MathWorld explains what an isosceles triangle is and how it compares with equilateral, and scalene triangles. The altitude and area of these triangles are also discussed.
CK-12 Foundation
Ck 12: Elem Math: Classifying Triangles Within Composite Figures
[Free Registration/Login may be required to access all resource tools.] In this learning module, students are presented with a composite figure and must identify the types of triangles within it. An accompanying video demonstrates a...
Math Planet
Math Planet: Pre Algebra: Triangles
Learn about the types of triangles by taking a look at an example and a video lesson.
Oswego City School District
Regents Exam Prep Center: Triangle Information
This Oswego City School District site from the Regents Exam Prep Center provides an explanation of the classifications of triangles both by sides and by angles. Pictures are also included.
Math Is Fun
Math Is Fun: Right Angled Triangles
The resource investigates right triangle. Topics explored are isosceles, scalene, and 3,4,5 triangles. Examples, illustrations, and definitions are included.
Mocomi & Anibrain Digital Technologies
Mocomi: Types of Triangles
Explore the different types of triangles and other properties.
ClassFlow
Class Flow: Understanding Basic Triangles
[Free Registration/Login Required] This lesson presents an introduction to triangles and the methods of identifying them. It includes opportunities for students to interactively identify triangles. It also includes: assessment questions...
ClassFlow
Class Flow: Classifying Triangles
[Free Registration/Login Required] This lesson covers methods of classifying triangles, both according to the length of their sides and by the measure of their interior angle.
Khan Academy
Khan Academy: Identify Triangles by Side Lengths
Practice identifying triangles by their side-lengths as equilateral, isosceles, or scalene. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
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."
Illustrative Mathematics
Illustrative Mathematics: 4.g Lines of Symmetry for Triangles
The division of triangles into scalene, isosceles, and equilateral can be thought of in terms of lines of symmetry. Aligns with 4.G.A.3.
Oswego City School District
Regents Exam Prep Center: Geometry Vocabulary Resources
A list of geometry definitions and a matching activity.