CK-12 Foundation
Ck 12: Trigonometry: Pythagorean Theorem to Classify Triangles
[Free Registration/Login may be required to access all resource tools.] Use the Pythagorean Theorem to determine if triangles are acute, obtuse, or right triangles.
Texas Instruments
Texas Instruments: Try Angle?
In this activity, students investigate properties of triangles by randomly generating possible side lengths for triangles. They learn to determine if three line segments can form a triangle. They also learn to classify triangles as...
CK-12 Foundation
Ck 12: Elem Math: Classifying Right Obtuse or Acute by Angle Measure
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on how to classify triangles based on angle measures.
Beacon Learning Center
Beacon Learning Center: Triangles Side by Side
This comprehensive web lesson describes how to classify triangles by their angle and side measurements. It provides real-world examples and exercises for students to practice the skill.
Oswego City School District
Regents Exam Prep Center: Angles and Triangles
On this site a viewer can learn about the different types of triangles, and categorized by either angles or sides. Tutorials are also included for interior and exterior angles of triangles. A teacher resource page includes a lesson plan...
Khan Academy
Khan Academy: Identify Triangles by Angles
Practice identifying triangles by their angles as acute, right, or obtuse. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
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.
CK-12 Foundation
Ck 12: Elem Math: Classifying All Types of Triangles by Lengths of Sides
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on classifying triangles based on length of sides.
CK-12 Foundation
Ck 12: Elem Math: Classifying Triangles by Identifying the Number of Equal Sides
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on classifying triangles based on the number of equal sides.
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.
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 Angles
Students can practice classifying triangles based on angle measurements through a series of self-check exercises and timed learning games.
Texas Instruments
Texas Instruments: Classifying a Triangles by Their Angle Measure Using Cabri Jr
This activity uses Cabri Jr to classify triangles according to their angle measure. [Requires Adobe Reader.]
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.
Math Open Reference
Math Open Reference: Triangle Quiz
Students are assessed on different types of triangles. Definitions of the triangles are included.
Louisiana Department of Education
Louisiana Doe: Louisiana Believes: Eureka Math Parent Guide: Angle Measure and Plane Figures
A guide to support parents as they work with their students in angle measure and plane figures.
ClassFlow
Class Flow: Angle This Way
[Free Registration/Login Required] Students will identify right, acute and obtuse triangles using many interactive tools available in ACTIVstudio 3.0. Students will be engaged using a magnifier tool, the fill tool, and drag and drop and...
Khan Academy
Khan Academy: Area of Triangles
Practice finding the area of right, acute, and obtuse triangles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
University of Saskatchewan (Canada)
University of Saskatchewan: Trigonometric Functions
This site examines the six trigonometric functions from a right triangle point of view. Provides information, examples, and lots of exercises for understanding.
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...
Merriam-Webster
Merriam Webster: Dictionary Illustration: Types of Triangles
A labeled illustration of six different types of triangles.
Sophia Learning
Sophia: Triangle Height: Lesson 2
This lesson will demonstrate how to locate the height in an obtuse, right, and acute triangle. It is 2 of 5 in the series titled "Triangle Height."
Sophia Learning
Sophia: Triangle Height: Lesson 4
This lesson will demonstrate how to locate the height in an obtuse, right, and acute triangle. It is 4 of 5 in the series titled "Triangle Height."
Wolfram Research
Wolfram Math World: Cut the Knot! Angles
Very good site with links to reviews of various angles.