RailwayRouteOptimization/scripts/Draw/Shape/ShapePolygonAFCP/doc/ShapePolygonAFCP_proc_en.html

<ol>
  <li>Enter the degree of the polygon (number of edges / corners) in the
  options tool bar. Valid numbers range from 3 to 99.</li>
  <li>Set the center of the polygon using the mouse or enter a coordinate in
  the command line.</li>
  <li>Set the middle point of one side of the polygon.</li>
</ol>