As you can see if I want to make sure the diameter of the hole, I have to get a print out of this drawing and keep the ruler and make sure these two points are on the same horizontal line.
Is there any software that can do the work of a ruler? That means while keeping the drawing on the computer screen, intended software can create a horizontal line to make sure that these two points are on the same horizontal line.
Let we say drawing is in the MP4 Video (.mp4) file. Problems belong to YouTube videos.
True projection will give you the results you're looking for without a ruler, if in doubt you could always add a plane or a construction line...