nonagon - 9 sided polygon or 9-gon
Free Nonagonal Number Calculator - This calculator determines the nth nonagonal number
Free Polygons Calculator - Using various input scenarios of a polygon such as side length, number of sides, apothem, and radius, this calculator determines Perimeter or a polygon and Area of the polygon. This also determines interior angles of a polygon and diagonals of a polygon as well as the total number of 1 vertex diagonals.