I would like to measure as in the screenshot but I am forced to choose Point To Point to get approximately close to the desired measurement.
When I select the arcs with Point to Point disabled, it measures across from the endpoint of arcs on either side in all the three situations of "Center to Center", "Minimum" and "Maximum" distance.
What am I doing wrong here? How do I have it snap? Yes, the tube is at an angle so strictly speaking it is an ellipse on the model.