[RESOLVED, thanks anyway]
I would like to use the Surface Object to create closed polylines using connected line segments (much as one would do in a CAD program). I have no trouble making this work with straight line segments, but have not had any success in determining if I can make an arc segment rather than a complete ellipse with the Surface object (such as a 45 degree segment or 90 degree segment from angle x to angle y). I will be calling the segment instructions from a data table to create profiles of existing parts. For example, if the first segment the user selects, is a straight line 5 units to the right, the data table might contain three parts with that first segment length, and will then present the user with the possible next segments; e.g. 3 units at 90 degrees (from the end of the first segment); 4 units at 90 degrees, or 3.5 units at 45 degrees. Some of these line segments will need to be arcs; e.g. a 90 degree arc from 30 degrees to 120 degrees with a radius of 2 units. These are the segments I've not been able to make work, and help or guidance would be appreciated.

Thanks for any assistance.