• Cube Nets
Great visualization challenge! Shows arrangements of squares. The challenge is to find the 11 arrangements that will fold into a cube.

• Cut Out Nets
Nets of the Platonic solids can be folded one side at a time and the shape rotated freely at any point in three dimensions. Fascinating!

• Cutting Corners
A cutting tool allows any one of three simple shapes to be sliced into parts along any straight line. Shapes can be rearranged, rotated, and flipped.

• Franklin Institute Online
Franklin Institute Online provides a hotlist of math websites on geometry topics, including a website of many fabulous pictures of fractals.

• Funschool.com
The Funschool website contains mathematical games on number concepts and operations, fractions, decimals, percents, geometry, probability, patterns, and equations.

• Geoboards
The NLVM library has four geoboards. The first measures areas and perimeters. The circular board has pins in a circular arrangement. The isometric board has pins in a triangular arrangement (like isometric dot paper). The coordinate board shows coordinates for each peg when the cursor is on it. It measures the slope and distance between two points joined by a band and then the perimeter and area of banded shapes.

• Geometry vocabulary
This page would be an excellent resource for any upper elementary students, or adults, who may want to brush up on their geometry vocabulary. Topics include angles, triangles, circles, and many other topics, with notes and diagrams to represent to concepts to the user.

• Isometric Drawing Tool
Cubes and any face of a cube can be drawn on an isometric grid. The drawings created can be rotated on the grid. The drawing can also be viewed in a second window that shows the drawing as a three-dimensional object that can be slowly rotated around three separate axes. It takes a little practice but this is an amazing tool.

• Key Curriculum Press
The Key Curriculum Press website that serves mathematics educators with a list of publications and software and free downloadable demonstration copies of its dynamical geometry software, Geometer's Sketchpad.

• Math Forum
As part of the Math Forum website, this page nicely divides into different sub-categories of elementary geometry. These links can be an excellent resource for students to review earlier geometry concepts or to use as a reference when just beginning a new concept.

• Maze Game
Provides practice with coordinates. The user plots points to guide a robot through a mine field.

• Mirror Tool
A nice tool for early investigations of mirror or line symmetry.

• ProTeacher.com
This page provides numerous resources for teaching about shapes. The links include lesson plans for teachers along with many printable sheets for students to use. Includes lessons on basic shapes, as well as platonic solids.

• Pythagorean Relationship
This compelling, dynamic proof of the Pythagorean relationship uses the idea that rectangles and parallelograms with the same height and base have the same area.

• Shape Sorter Tool
After selecting a Venn diagram and labels for each loop, shapes are produced and the user must correctly place them in the diagram. Labels are properties of angles and sides.

• Slicing Platonic Solids
Any one of five Platonic solids can be shown in a window that is a plane of intersection with the solid. As the solid is rotated freely, the portion above and below the plane changes. The plane intersection shape is always shown in a second window. This is a virtual version of "Water Slices," Activity 21.37.

• Space Blocks
This applet allows the user to create "buildings" made of cubic blocks rather easily. Each new block snaps to a block in the ongoing construction.

• Tangrams
These virtual tangrams can be manipulated freely. Plus, there are 14 puzzle shapes to fill in with all 7 tangrams.

• The World of M.C. Escher
The World of M.C. Escher website provides information on creating tessellations and on downloading a free demo of the program Tesselmania.

• Visualizing Transformations
This four-part applet provides an excellent exploration of the three rigid-motion transformations including composition of two transformations.