WOLFRAM|DEMONSTRATIONS PROJECT

Albrecht Dürer's Nonagon of 1525

​
step
1
2
3
4
5
6
7
8
9
Draw a circle and three arcs as for a regular triangle.
This Demonstration shows a nonagon constructed in seven easy steps using straightedge and compass. The nonagon is not regular. For example, one angle at the midpoint is approximately 39° 35' instead of 40°.