What points does one measure from and to when referring to rafter tables on a framing square.?

Question:I'm framing a hip roof and I'd like to use the rafter tables on my framing square to determine the rafter lengths. The problem is that I don't know where the lengths are measured from. Fo instance, is it from the long point of the head cut to the highest point of the birdsmouth or other? Thanks in advance for the help.

IM

Answers:
Roof framing is a geometric function.
Draw the triangle that is determined by the distance between the outsides of the two walls and your roof slope.

The rafter run (length) is the length of the angle, minus 1/2 the thickness of the ridge, plus the overhang (eve).

Set your stair gages on the framing square for your roof pitch, crown your material and mark the ridge (plumb) cut.
Use the metered dimensions along the wide blade of the square to determine the distance to the seat cut (birdsmouth) rafter run.

If your rafter tails are plumb cut, roll the sq, over and flip it end for end to mark that cut.

Make your cuts, you now have your pattern.