National Council of Teachers of Mathematics
The Math Forum: Elementary Geometry Circles
The Math Forum offers an archive of question and answer sessions on circles and how they relate to geometry.
Rice University
Rice University: Cynthia Lanius: Mathematics of Cartography
Can there be a connection between map making and math? Explore the mathematics of cartography in this resource that integrates web-based instruction, mathematical problem solving, geometry, history, and art. Interesting information and...
Ducksters
Ducksters: Kids Math: Circle Geometry
Circle Geometry math for kids contains information for students to learn about terms radius, diameter, circumference, chord, and pi.