Anyway, I decided to see if I could decipher the 2010 UK Team Redcar task model. This model has 2 crossing jack rafters offset/skewed from the plate line and are rotated into the roof surface. The two jack rafters are skewed from the plate line at different angles to make deciphering the task model a real challenge. I used the Rabattement Surface drawing technique to draw out the miter and bevel angles of the rotated jack rafters. I'm guessing in carpentry competitions the apprentices would have used the draw down technique so they could fit the roof surface on their drawing board.
Here's my deciphered ground plan and Rabattement Roof Surface drawing of the 2010 UK Team Redcar task model. I did come up with the same miter and bevel angles for the rotated jack rafters, but it gets pretty messy just drawing in one of the rotated jack rafters. The key to establishing the mite angle of the jack rafters rotated into the roof surface is the Hip Rafter Internal Edge On Roof Surface line drawn on the roof surface using the dimension of the profile rafter block ,40mmx60mm, rotated perpendicular to the hip rafter backing line.