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: Nonagon (9 Gon)
Learn about nonagons with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.