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.

Here is a site that clearly and thoroughly explains how to solve right triangles for any missing side or angle given any two pieces other sides or angles. There are example problems solved, problems for the student to attempt, and...

Here is a site that clearly and thoroughly explains the trigonometry of a right triangle, including finding the values of all six trig functions given a single value. There are example problems solved, problems for the student to...

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.

[Free Registration/Login may be required to access all resource tools.] Find distances using angles expressed as bearings. Here you'll learn how to relate right triangle relationships to course bearings.

This section explores the relationship between right triangles, circles, and trigonometry. It investigates how a right triangle that is set inside a circle and rotates around the circle is connected to trigonometric functions and their...

In this set of questions, students practice identifying side-side-side similarity among triangles. Includes hints.

[Free Registration/Login may be required to access all resource tools.] The video discusses a brief overview of circles, rectangles, squares, and triangles and helps students determine which shape is shown and why. The video is followed...

Wikipedia explores the history of the Bermuda Triangle and supposed associations with paranormal activities. Content includes a look at the first mention of the Bermuda Triangle, its growth in popularity, skeptical responses, and famous...

In this activity the Students can use Cabri Jr. to investigate the Triangle Inequality Theorm and make conjectures about their findings.

Thought provoking entry discusses the many outrageous ideas about the so-called mysterious disappearances of the Bermuda Triangle area in the Atlantic Ocean.

Solve geometry problems with various polygons by using all you know about similarity and congruence.

Demonstrates how to translate, set up, and solve basic right-triangle word problems.