Test your knowledge on the attributes of triangles. There are eleven levels that may be completed with or without a timer.

Provides definitions, formulas, and examples relating to the special right triangle, the 30-60-90 degrees.

Student will use primary and secondary sources to gain a richer understanding of women's activism and how the Triangle Shirtwaist Fire led to changes in labor and safety regulations in America.

[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on finding the missing angles in triangles.

[Free Registration/Login may be required to access all resource tools.] Use right triangle ratios to solve for sides of triangles.

[Free Registration/Login may be required to access all resource tools.] In this lesson students prove two triangles are congruent with the Angle-Side-Angle and Angle-Angle-Side shortcuts. Students examine guided notes, review guided...

Explore and measure a variety of triangles.

[Free Registration/Login may be required to access all resource tools.] This concept teaches students what it means for two triangles to be congruent and how to identify corresponding parts of congruent triangles. Students examine guided...

[Free Registration/Login may be required to access all resource tools.] Use the Triangle Proportionality Theorem and its converse.

This lesson will demonstrate the use of CPCTC in triangle congruency proofs.

[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on identifying rectangles, squares, circles and triangles.

What better way to get to know your students than with a 1:1 interview. Today you will interview each student on their knowledge of triangles and their ability to separate them from other shapes.

Students can practice classifying triangles based on angle measurements through a series of self-check exercises and timed learning games.

Students can practice classifying triangles based on side lengths through a series of self-check exercises and timed learning games.

Using the Compass tool in Cabri Jr., students will construct an equilateral triangle, and check the length of each side. When a vertices is moved using the Alpha hand, the triangle remains equilateral.

A complete reference guide to congruent triangles. It provides definitions, examples, and an interactive activity that enhances further explanation. Includes links to related topics.

Given two similar triangles and some of their side lengths, find a missing side length.

Comprehensive lesson features proofs and examples that establish that the theorem that states "the sum of the measures of the interior angles of a triangle equals 180 degrees" is actually true.

This lesson plan provides students with an opportunity to practice drawing and measuring triangles and angles. It also shows pictures and gives definitions of each type of angle and triangle.

[Free Registration/Login may be required to access all resource tools.] Classify different types of triangles by their angles.

[Free Registration/Login may be required to access all resource tools.] Determine an alternate formula for a triangle's area.

Demonstrates the logic behind the formula for the area of a triangle. Includes several practice problems and their explanations.

This activity illustrates the Triangle Inequality and the conditions necessary for a triangle to be formed from three straight lines.

[Free Registration/Login may be required to access all resource tools.] Finding unknown sides in a triangle using other sides and angles.