The meter was at the same level as the exhaust port and held directly above the end of his template. Sorry Rob... no buffer!
I'm not great at triangles but if you have 15" out, turn 45 degrees and go another 15" then what is the measurement of the long side of this triangle? It isn't a right-angle so the Pythagorean theorem can't be used directly, at least without throwing in some trig at the end.
Any math wiz out there this AM?