Joe Bartok might have been able to use math, trigonometry, to calculate the intersection of the two valley rafters and two cripple hip rafters with the sloping ridge. However, the easiest way for me to find the intersecting point is to use Dachausmittlung (roof slope averaging).
The main profile rafter slope is 4:12 (18.43495°). The intersection of Valley Rafters and Cripple Hip Rafters determines the 22.27275° Roof Slope Angle on the front of this roof in plan view. By using Dachausmittlung (roof slope averaging) you can locate the intersection of the averaging lines and draw in the hip rafter in plan view to intersect the sloping ridge on plan view.