dodecagon

In geometry, a dodecagon, or 12-gon, is any twelve-sided polygon.

==Regular dodecagon== thumb|upright=1.5|Three squares of sides R can be cut and rearranged into a dodecagon of circumscribed circle|circumradius R, yielding a that its area is 3R2 A regular dodecagon is a figure with sides of the same length and internal angles of the same size. It has twelve lines of reflective symmetry and rotational symmetry of order 12. A regular dodecagon is represented by the Schläfli symbol {12} and can be constructed as a truncated hexagon, t{6}, or a twice-truncated triangle, tt{3}. The internal angle at each vertex of a regular dodecagon is 150°.