Albrecht Dürer's Heptagon of 1525

This Demonstration shows a heptagon constructed in six easy steps using a straight edge and compass.

The heptagon is not regular. For example, one angle at the midpoint is ≈ 51° 19' instead of 360° / 7 ≈ 51° 26'.

For more information, see A. Dürer, Underweysung der Messing mit dem Zirckel und Richtscheyt (Treatise on Mensuration with Compass and Ruler), 1525.

Ralf Schaper