Enneagon vs. Nonagon — What's the Difference?

(geometry) A polygon with nine sides; a nonagon.

In geometry, a nonagon () or enneagon () is a nine-sided polygon or 9-gon. The name nonagon is a prefix hybrid formation, from Latin (nonus, "ninth" + gonon), used equivalently, attested already in the 16th century in French nonogone and in English from the 17th century.

A polygon or plane figure with nine sides and nine angles; a nonagon.

A polygon with nine sides and nine angles.

(geometry) A polygon with nine sides and nine angles; an enneagon.

A plane figure or polygon having nine sides and nine angles.

A nine-sided polygon