How to square a building?
a(squared) + b(squared) = c(squared). So take the two measurements, 16′ and 20′, square each one and add them together, you’ll get 256 and 400. Now add them together, and you get 656. This number is your diagonal measurement squared. So take the square root of that, and you get 25′ 7-11/32″ (or 25′ 7-3/8″ for a framer). That is your diagonal measurement. So your building should be that distance diagonally from corner to corner. Check them all to make sure. If it isn’t working out, then something is wrong. I always figure if I’m within about an eighth of an inch when framing I’m in great shape.
