Regular nonagon
<a href="https://en.wikipedia.org/wiki/User:Gustavb" class="extiw" title="en:User:Gustavb">Gustavb</a>
Created by <a href="https://en.wikipedia.org/wiki/User:Gustavb" class="extiw" title="en:User:Gustavb">Gustavb</a> using <a href="//commons.wikimedia.org/wiki/User:Gustavb/regular_polygon.pl" title="User:Gustavb/regular polygon.pl">User:Gustavb/regular_polygon.pl</a>.