National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Polyhedra Classification
This question and answer site provides a lot of basic information about polyhedra. The five regular polyhedra, "The Platonic Solids," are described.
University of Toronto (Canada)
Question Corner: Higher Dimension Geometry
Use this site to discover how we represent higher dimensional objects in mathematics and how one might draw a four dimensional object on two dimensional paper and modeling fourth degree tetrahedron.
Other
Polyhedra: The Five Platonic Solids
A brief site that includes some activities to understand the figures.
National Council of Teachers of Mathematics
The Math Forum: Polyhedra Nets Paper
Contains six examples of polyhedra nets (cube, tetrahedron, octahedron, dodecahedron, icosahedron, cubosctahedron).
Other
Ohio Resource Center: Shadows
This applet helps students visualize the shapes of shadows cast by a cube with a light coming from different angles. This helps students visualize shapes from different angles and to identify, sketch and classify the cross-sections of...
Sophia Learning
Sophia: Drawing Three Dimensional Objects: Lesson 2
This lesson demonstrates how three-dimensional objects can be drawn in a three-dimensional space. It is 2 of 5 in the series titled "Drawing Three Dimensional Objects."
ClassFlow
Class Flow: Soma Cube
[Free Registration/Login Required] In this flipchart, students use the drawing tools in Activstudio to create three dimensional shapes using interactive cubes.
ClassFlow
Class Flow: Summing Differences
[Free Registration/Login Required] In this flipchart, students apply their understanding of geometric properties and relationships. Students use geometric properties and relationships to describe, compare, and draw two-dimensional shapes...
Free Math Help
Free Math Help: Classification of Polygons and Triangles
The Geometry session explores the classification of polygons and triangles. Definitions and examples are included.
ClassFlow
Class Flow: Impossible Objects
[Free Registration/Login Required] In this lesson, students use math to create two dimensional illusions in the form of impossible objects. Students use the drawing and measuring tools to create mathematical art.
Shmoop University
Shmoop: Basic Geometry: Volume of Spheres
The geometry resource investigates the volume of a sphere. Formulas, examples, and practice exercises are included.
ClassFlow
Class Flow: Nets
[Free Registration/Login Required] In this flipchart, students explore geometric sense by interacting with plane diagrams that create a three-dimensional shape.
Shmoop University
Shmoop: Basic Geometry: 3 D Objects (Prisms, Cylinders, Cones, Spheres)
The geometry resource investigates three-dimensional objects. Objects include prisms, cylinders, cones, and spheres. Detailed examples and practice exercises are included.
Calculator Soup
Calculator Soup: Geometric Shapes
This reference lists formulas for geometric shape measurements and offers links to online calculators.
Wolfram Research
Wolfram Math World: Frustum
Math World site offers the definition of frustum and links to view a frustum of a pyramid, cone, and sphere.