The hip rafter overhang length is calculated as follows. The projection
of 800 mm divided by the 250 mm run unit = 3.2 units of run.
Overhang = length of hip rafter per unit of run (384.1 mm) times units
of run (3.2) = 1229.1 mm. A double cheek tail cut is laid out on the
overhang as shown in figure 10. Note that the 90 degree overhang plumb
lines are drawn on a hip that is at an angle of 45 degrees to
the fascia boards.