CK-12 Foundation
Ck 12: Interactive Geometry: 5.4 Constructions of Regular Polygons
Learn how to construct regular polygons.
Calculator Soup
Calculator Soup: Regular Polygon Calculator
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.
Mathigon
Mathigon: Geometry: Polygons and Polyhedra: Platonic Solids
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:...
Other
Visnos: Polygons
Create regular and irregular polygons and determine the angles and side lengths with this interactive exercise. Use Safari or Chrome browser.
Mathigon
Mathigon: Geometry: Polygons and Polyhedra: Quadrilaterals
This lesson focuses on quadrilaterals which can fall into multiple categories based on the number of sides and the angles.