Chiral enneagonal symmetry

Chiral enneagonal symmetry, also known as kiennic symmetry and notated as I2(9)+, is a 2D spherical symmetry group. It is the symmetry group of the enneagon with rotational symmetry but no reflections.

Subgroups

 * A2+ (maximal)
 * I×I

Convex polytopes with I2(9)+ symmetry

 * Enneagon (regular)