Lesson Plan
Illustrative Mathematics

Are These Right?

For Teachers 3rd - 5th Standards
Is that a right triangle or a wrong triangle? Young mathematicians look at eleven different shapes and use a measuring tool of their choice to determine which triangles have right angles. Consider cutting out sets of the shapes to...
Activity
Beacon Learning Center

Beacon Learning Center: Triangles Side by Side

For Students 3rd - 8th Standards
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.
Activity
Texas Instruments

Texas Instruments: Classifying a Triangles by Their Angle Measure Using Cabri Jr

For Teachers 9th - 10th
This activity uses Cabri Jr to classify triangles according to their angle measure. [Requires Adobe Reader.]
Activity
AAA Math

Aaa Math: Types of Triangles Based on Angles

For Students 3rd - 5th Standards
Students can practice classifying triangles based on angle measurements through a series of self-check exercises and timed learning games.
Activity
Texas Instruments

Texas Instruments: Try Angle?

For Teachers 6th - 8th Standards
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...