obtaining a line from a circle, arc or polygon

i know autocad draws based on lines, i want to select a line that is part of a polygon, a circle or an arc, so my program can recognize it as a line and start working with it.. any ideas?

 

HUH?

 

The lines that make up circles are only on the screen. If you do a REGEN
and your VIEWRES is set high enough, the lines disappear and you see a
smooth circle. The circles are not based on lines. But here's a subroutine
to break a circle or arc into segments. I don't think there's any
reasonable way to get the lines that ACAD uses to draw coarse circles.

Code:

http://groups-beta.google.com/group/autodesk.autocad.customization.vba/browse_frm/thread/537f791adee0000/1f05a10ee4b9bc89

of a polygon, a circle or an arc, so my program can recognize it as a line
and start working with it.. any ideas?

 

No, AutoCAD isn't "based on lines." In addition to LINE objects, it also
uses ARCs, CIRCLEs, Polylines, LWPolylines, SPLINES, and ELLIPSES, all of
which are accurate mathematical representations. If you want to work with a
circle or arc, you must be ready to deal with a true circle or arc, not a
"line."
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