The word is, surprisingly, "nonagon".
November
Ennead, enneadic, ninth, nonagon, novenary...
Because nonagon means 9 sides
Nonagon is the appropriate word for a nine sided plane figure
nonagon is one good word
A nonahedron, which is a 3D shape with 9 faces.
First you must determin what the "apothem" is, and by that i mean what the hell that word means.
A nonagon is a polygon with nine sides. The prefix "nona-" in nonagon comes from the Latin word for "nine." Each side of a nonagon connects to two other sides, forming a total of nine straight sides that enclose the shape.
Nonagonal.
nonaligned?
nonagon nonahedron nonuplets
Polygon, for many-sided.