Is there an easy way to find the accuracy of a construction given a straight-edge and compass?
For instance setting the point of a compass on an existing line. How do I know how exact that is? Or more critical, putting the compass on "the point" that is the intersection of two lines that intersect at a very small angle.
OR after setting down a straight edge to draw a line through two points, how do I determine the accuracy of the line that is drawn?
Is there a computer construction program that also gives the accuracy of the result?
Make constructions of angles like $60^0, 90^0 $ and some bisection of straight lines in elementary geometry. Verify their accuracy by measurement.
The question is about things like bluntness of cone at end of drawing pencil point that creates a small offset from the ruler edge to a straight line or the accuracy of placement of compass point at center of circle by young eyes versus the myopic.. etc., that is about all.
You can scan, zoom and verify accuracy of your work if you so want, but as you learn the subject more you may find these quite irrelevant.Computer may not be employed to help hand generated work in this way.