[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on identifying the properties of squares.

A comprehensive list of 2D shapes and 3D solids with everything from a triangle to a dodecahedron. Includes illustrations and short descriptions of attributes for each.

[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to calculate the area of composite shapes. Students examine guided notes, review guided practice, watch instructional videos and...

[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...

The introduction of this lesson has students verifying the famous Pythagorean Theorem with a hands-on proof. Students will then apply the Theorem in one of two ways: by solving for the side lengths of a right triangle and by determining...

Explore adjacent angles with this helpful reference tool. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.

For this mini-lesson, you will learn about the definition of geometric shapes and view many examples. You can check out the interactive simulations to know more about the lesson and try your hand at solving a few interesting practice...

Students reflect on their work and apply what they've learned about the characteristics of geometric figures. Includes a learning game to be played with a partner.

In this lesson plan on area and perimeter, 3rd graders will learn how to find the area and perimeter of rectangles by applying formulas.

An interactive site that instructs and demonstrates how to find the fourth angle of a quadrilateral. This site also has many links to other interactive lessons.

This Q & A forum has a question answered on how to find the apothem of a hexagon.

Finding the third angle of a triangle becomes easier by the explanation and examples presented.

This one page Mathworld site has a number of examples of semiregular tessellations. A definition and a small amount of related information is given at the bottom of the page.