Once at "mathematics", scroll down to Geometry. Geometry sites related to tiling, non-euclidean geometry, puzzels, and "the fine structure constant." Site is maintained and copyrighted by Cornell University Theory Center: Math and Scie

Public Broadcasting site. Lesson plans and activities.

Public Broadcasting site for geometry resources.

Interactive materials for visually exploring geometrical concepts. Very interactive. Developed as part of The Geometry Center at the Univeristy of Minnesota.

"The Geometry Center is a mathematics research and education center at the University of Minnesota.

Geometry facts, theorems, some proofs. Very colorful format. Music is loud when you reach the site, so you may wish to turn down the volume.

"These pages contain usenet clippings, web pointers, lecture notes, research excerpts, papers, abstracts, programs, problems, and other stuff related to discrete and computational geometry.

Lesson plans and activities including exploration of shapes, proof of pythagorean theorem, scaling the pyramids, the geometry of lenses, the math of music and more.

Lesson plans and activities including truss strength, dome geometry, quilts, and more.

Thirty activities based on hyperlinks to web resources. Activities begin with "What is Mathematics?" and progress through pythagoras´ observations of music, patterns on ukranian Easter eggs, symmetry in the alphabet, butterflies, and more.