david weaver
In all seriousness, I can't imagine why you'd ever have to measure.

When I first started, I was all over all of the angles, making jigs, and an engineering friend of mine made diagrams. They are actually still on the wall (more proof that I am not one to clean up anything unless forced, and they occupy a space that just isn't used).

When I started to work mostly by hand, I kind of rebelled against measuring things that didn't need to be measured (including workpieces - if able, set out the basic dimensions from the start then mark off the piece and measure as little as possible).

Until this topic came up here a year or two ago, I didn't have a clue what my final angle was, but was afraid I'd be embarrassed to find that it was 28 degrees or 38 degrees or something. It ended up being precisely in the middle. Proven good through use of tools. The results are there - other than discussion, that eliminates the need to measure.