The constructible regular 12-sided Polygon with Schläfli Symbol . The
Inradius , Circumradius , and Area can be computed directly from the formulas for a general
regular Polygon with side length and sides,

(1) | |||

(2) | |||

(3) |

A Plane Perpendicular to a axis of a Dodecahedron or Icosahedron cuts the solid in a regular Decagonal Cross-Section (Holden 1991, pp. 24-25).

The Greek, Latin, and Maltese Crosses are all irregular dodecagons.

**References**

Holden, A. *Shapes, Space, and Symmetry.* New York: Dover, 1991.

© 1996-9

1999-05-24