http://nlvm.usu.edu/en/nav/frames_asid_128_g_3_t_3.html - Counting faces, bases and vertices

http://nlvm.usu.edu/en/nav/frames_asid_131_g_3_t_3.html - Platonic Solids that can be rotated.

http://www.harcourtschool.com/elab/index.html - click on a grade and you can try different applets.

http://www.fi.uu.nl/toepassingen/00297/toepassing_wisweb.en.html - all the nets and you can fold them electronically.

http://illuminations.nctm.org/tools/tool_detail.aspx?id=84 - Nets that turn into a cube.

http://illuminations.nctm.org/tools/tool_detail.aspx?id=70 - Geometric Solids

http://illuminations.nctm.org/tools/shapesorter/shapesorter.asp - Shape Sorter for the Venn Diagram

http://illuminations.nctm.org/swr/list.asp?Ref=2&Std=2 - All of the Geometry on Illuminations

http://www.mste.uiuc.edu/users/carvell/3dbox/default.html - Surface area and volume while cutting

out edges of a flat sheet of paper. (Challenge for the 4th and 5th grade)

http://www.fi.uu.nl/toepassingen/00198/toepassing_wisweb.en.html - Views of 3D objects (Challenge for the 4th and 5th grade)