I think what makes the drawings confusing, at least in this post, is the angle they are presented to the reader. We are used to measuring angles off of the horizon or a line perpendicular to the horizon. If it is rotated it can cause confusion.
For example, in the first pic the chair seat is parallel to the horizon but if you were to see it in a room the seat would be angled so your brain wants to make the adjustment because it not used to seeing a chair presented at this angle.
In the last pair of drawings , Section A-A and Section B-B, the line that is perpendicular to the seat bottom that is used to measure the angle of the leg isn’t presented to the reader as perpendicular. So we want to rotate them. And if we were to measure the angles on the bench, the seat would be flat on the bench (rotated from the drawing).
Not a criticism, just a possible explanation as to why they seem confusing. Yes all the pertinent information is there. It’s just not intuitive as the drawings are currently presented.
In reply to Sam Yamron。< / p >
I used to do the same thing. Until I ended up with a low six legged pie safe with too much splay. And the damn cup holder was off kilter about 18 degrees.
Seriously, I’m in the Frankenstein school of design, too.