Wolfram Demonstrations Projecthttp://demonstrations.wolfram.com/An Open Resource of Interactive Mathematica VisualizationsCopyright 2009 Wolfram Demonstrations Project & ContributorsPolyhedra, Spheres, and Cylindershttp://demonstrations.wolfram.com/PolyhedraSpheresAndCylinders/]]>http://demonstrations.wolfram.com/PolyhedraSpheresAndCylinders/Cube-in-a-Sphere Illusionhttp://demonstrations.wolfram.com/CubeInASphereIllusion/]]>http://demonstrations.wolfram.com/CubeInASphereIllusion/Nested Regular Polygonshttp://demonstrations.wolfram.com/NestedRegularPolygons/]]>http://demonstrations.wolfram.com/NestedRegularPolygons/