Explore the world of congruent triangles in this mini-lesson. Provides a definition and examples that help with understanding their properties. Includes a short video and practice questions with answers.

This site from the University of Saskatchewan provides an explanation of similar triangles, the Pythagorean theorem, and the distance between arbitrary points in a plane. Example problems for each of these concepts are provided.

Find explanations of the ways to prove triangles are congruent. There is a link for Congruence Of Triangles, Part II to find the proofs of some ways to prove congruence of triangles from other postulates (i.e. Assume SAS prove ASA).

In this lesson, students learn to inscribe regular polygons inside a circle.

[Free Registration/Login may be required to access all resource tools.] In this lesson, students learn how to translate a figure. They examine guided notes, review examples, watch instructional videos, and try practice problems.

The Chinese character mark formerly known as "Tan" is the first of two lessons to introduce first grade students to geometry using tangrams. This lesson incorporates history, math, and language arts. In this lesson students will be able...