I have just started to create a simple drawing. It is a closed contour involving splines, arcs and some straight lines. I tried to define the distance between the midpoint of the arc and one straight line of mine. However, after I did so, there was no error, but the midpoint that I marked was not even on the arc anymore. Here is a diagram

The arc is on the top, and the line is at the bottom.

Please help.

Message was edited by: Aaron Zheng