Willow Tree
Interior Angles, Exterior Angles, and Diagonals of Polygons
How does the number of sides of a polygon affect the angle measures? Learners recognize a pattern in finding the total measure of interior and exterior angles and the number of diagonals. They use the patterns to calculate...
Math Open Reference
Math Open Reference: Polygons
Get the definition and properties of a polygon. Then explore such topics as: 1) types of polygon 2) area 3) Perimeter 4) angles associated with polygons and 5) names of polygons.
The Math League
The Math League: Figures and Polygons
This website has basic definitions for most polygons, regular and irregular.
Math Open Reference
Math Open Reference: Interior Angles of a Polygon
Learn about interior angles of a polygon with this handy reference guide. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: Center of a Polygon
A complete reference guide to the center of a polygon. It provides definitions and an interactive activity that enhances further explanation. Includes links to related topics.
The Math League
The Math League: Figures and Polygons: Nonagons
This site provides definitions and examples of the various types of polygons including nonagons.
University of Georgia
University of Georgia: Inter Math: Nonagon
This site gives the general definition of a nonagon with examples of a regular (convex) and irregular concave nonagons. There are links to related terms, challenging problems, more information, and the interactive check point involving...
Math Open Reference
Math Open Reference: Circumcircle
A handy reference guide to circumcircles. It provides definitions and examples that enhance further explanation. Includes links to related topics.