Now that indeed is good news. I hadn't thought about the door jamb method with a hammer gun, as all of my doubles are hammerless- good point--

What makes a drywall square, framing square etc work is the Pythagorean Theorum-- but here's a puzzlement, at least to me-- a roof with a 12/12 pitch is a 45% roof-- half of 45% is 22.5%, and half of 12 is 6-- But= when you want to step off common rafters for a 22.5% roof it is a 5/12 (unless it is a hip, then it goes to 5/17)-- huum- hey, that's just the way it works I guess.