Something from web about polyline

I would advise less experienced AutoCAD users that use the AREA command area, or by reading the value from the properties window for the polyline may inadvertently be misled. Well, I really value denoted as

Area is the result of a certain algorithm which gives the correct result only when surface polyline is not self intersecting, otherwise give error results. I am writing this because sometimes you get confused and never read anywhere about it. Try to lead polyline through the points in turn: (0.0) (10.0) (5.5) (5, -5) (0, 0) and examine its surface.

hm...Any comment?

I studiously avoid self-intersecting polylines so I've never encountered a problem with calculating area.

The moral of the story is, if you practice bad habits you'll get bad results. Just don't be surprised.

i always use polyline area - never been a problem

(never checked?!!)