as you know I am working on images, at this moment I am facing the following problem, I do not know how to measure the diameter of the line that is observed in the image that I attached, I could apply a little the theorem of Pythagoras, but I do not know if it is possible to do it in an image, for example in this case the image has a thick line, but in case the line is thinner than can be done?
I would like to know the diameter when the line is alone, because it is obvious that when there is a cross the diameter will change, I show it in the next image.

