eBook
CK-12 Foundation

Ck 12: Interactive Geometry: 5.4 Constructions of Regular Polygons

For Students 9th - 10th Standards
Learn how to construct regular polygons.
Interactive
Calculator Soup

Calculator Soup: Regular Polygon Calculator

For Students 9th - 10th Standards
Use this calculator to calculate properties of a regular polygon. Enter any 1 variable plus the number of sides or the polygon name. Calculates side length, inradius, circumradius, area, and perimeter.
Activity
Analyze Math

Analyze Math: Rotation Symmetry of Regular Polygons

For Students 9th - 10th Standards
An applet is used to investigate the rotation symmetry of regular polygons.
eBook
Mathigon

Mathigon: Geometry: Polygons and Polyhedra: Platonic Solids

For Students 9th - 10th
A Platonic solid is a polyhedron made up of only one kind of regular polygon, that looks the same from every direction. (In other words, the same number of faces meet at every vertex.) There are only five different Platonic solids:...
Activity
Other

Visnos: Polygons

For Students 1st - 8th Standards
Create regular and irregular polygons and determine the angles and side lengths with this interactive exercise. Use Safari or Chrome browser.
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.