Pick's Theorem
- Describes a theorem for finding an area of simple lattice polygons. Includes proof and Java applet simulation.
- http://www.cut-the-knot.org/ctk/Pick.shtml

Sliceform Models by John Sharp
- Three-dimensional objects constructed by slotting together a series of planar cross sections made from card. Downloadable templates in PDF, PS and Word formats.
- http://www.mathsyear2000.co.uk/explorer/slice/

Zome Edu
- Educational toys used to teach geometry and model building to create squares, spheres, stars and other regular shapes with sticks and connecting pieces. Products include kits and lesson plans.
- http://www.zometool.com/educators.html

Regular Polytopes
- Derivation of volume equations for regular polygons, polyhedra, and polytopes, with images.
- http://www.math.rutgers.edu/~erowland/polygons.html

Guy's Polyhedra Pages
- Vertex figures, filling, faceting diagrams, stellation, defining polytopes through generators, trimethoric and trisynaptic polyhedra, space-filling polyhedra, lost stellations of the icosahedron, and links.
- http://www.queenhill.demon.co.uk/polyhedra/

The Charged Particles Model
- Polytopes and optimal packing of p points in n dimensional spheres. Contains a java applet based on a model which allows for generation of multidimensional regular and semi-regular polytopes.
- http://presh.com/hovinga

The Geometry Junkyard
- Comprehensive list of links to sites on geometric properties of the shapes.
- http://www.ics.uci.edu/~eppstein/junkyard/polytope.html

The Mathematical Atlas - Polytopes and Polyhedra
- Collection of discussions regarding volume, vertices, dissection, g-holed tori, and other subjects.
- http://www.math.niu.edu/~rusin/known-math/index/52BXX.html