Unit Plan
Analyze Math

Analyze Math: Regular Polygons

For Students 9th - 10th Standards
The interactive tutorial examines the properties and formulas of regular polygons, inscribed circles, and circumscribed circles.
eBook
Mathigon

Mathigon: Geometry: Polygons and Polyhedra: More on Polyhedra

For Students 9th - 10th Standards
This lesson focuses on polyhedra other than the platonic solids; these include an Archimedean solid, a polyhedron made up of different kinds of regular polygons, that looks the same from every direction. There are 13 different...
Lesson Plan
Science and Mathematics Initiative for Learning Enhancement (SMILE)

Smile: Polyhedrons

For Teachers 9th - 10th Standards
This in-depth paper examines the idea of convexity. Euclid's Elements, the first geometry textbook, assumed convexity without mentioning the term.