Pairs or small groups work together to determine the height of a tree using similar triangles. Learners make a judgement which direction to let a tree fall to avoid hitting any structures. They then write letters to the principal...

Triangles are all about threes, and practicing proving postulates is a great way to get started. The first page of the activity provides a brief introduction of the different properties and postulates. The remaining pages contain...

Starting with similar triangles and dilation factors, this unit quickly and thoroughly progresses into the world of right triangle features and trigonometric relationships. Presented in easy-to-attack modules with copious application...

Learners determine the trigonometric relationships within a triangle as they construct a right triangle on the Ti-89. They find the sine, cosine, and tangent of various angles of their triangle construction.

Pupils investigate segments in a triangle by constructing a triangle using Cabri Jr. They construct segments within the triangle that lie on the midpoints of the triangle's sides. Learners then compare the slope of base of the triangle...

Pupils explore the midsegment of a triangle in the geometry lesson. They draw and measure the segment joining the midpoints of the two sides of a triangle and compare its length to the length of the third side of the triangle. The...

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

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

[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...

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

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

Explore and measure a variety of triangles.