I don't know what is so difficult to understand. Looking at the pipe image in post #34, you see it's a pipe that is bent. How can you measure it's length as if it was straight, not bent ? I've been told that I need to measure the bent angle of the pipe as well as the other straight areas, is there not a more intelligent way to do this, then having all these measurements at hand ?
The image is suppose to represent a pipe, use your imagination. I gave the measurements from top to bottom, the top would be the top of the pipe as seen in the image, the bottom, obviously the bottom of the pipe. Is there a formula to find out the length of the pipe as though the pipe did not have a bend, and was straight, or must the measurements of the bend of the pipe be known ?