It is a seven sided coin, an equilateral curve heptagon of constant breadth (3 centimetres) and mass 13.5 grams.
For example, sea stars display the symmetry of a pentagon or, less frequently, the heptagon or other polygons.
Apart from the heptagonal prism and heptagonal antiprism, no convex polyhedron made entirely out of regular polygons contains a heptagon as a face.
The badge is a black heptagon bearing a silver owl, the whole contained within a red annulet.
However, some geometrical constructions are not possible with those tools, including the heptagon and trisecting an angle.
The illustration shows an example in which the seven points are the vertices of a regular heptagon.
In a regular heptagon, in which all sides and all angles are equal, the sides meet at an angle of 5/7 radians, 128.5714286 degrees.
However, there exist arbitrarily large sets of points in general position that contain no empty convex heptagon.
