National Council of Teachers of Mathematics
The Math Forum: Suzanne Alejandre's Designs With Circles
In the Islamic culture, circles are considered to be a unit of measurement and the basis for the organization of space. This is illustrated at this site by a series of exercises.
Art Cyclopedia
Artcyclopedia: Chronological Listing of Draughtsman
ArtCyclopedia's complete list of draughtsmen from the 17th thru the 19th centuries. There are links to their biographies and works.
Dartmouth College
Dartmouth College: Mqed: Pattern
Young scholars learn about mathematical patterns and the art of designing repeat patterns. Lessons and assignments are included in this online resource.