Posted by Rallaz on Jan 28, 2013; 11:03am
URL: https://forum.librecad.org/manual-first-steps-tp5707490p5707520.html

Hello Claus,

A polyline is a sequence of vertexs (nodes) connected by a segment with bulge (curvature). If the bulge is 0 then it is a a straight line. Bulge are tangent of included arc / 4.
If the polyline are closed then are added a segment form last to first vertex.

Note that if the last and the first vertex coincides in space the polyline is open although, visually, seems closed.

Bob & Claus:
great work!!

Rallaz