Pick up a copy of the "Timber Frame Joinery & Design Workbook" from our online store:
http://st1.yahoo.com/tfguild/deswor.htmlthere are a couple very good articles in there describing the angles you are looking for,
or
use a good CAD 3D Modelor, (Modeler, Modellor?)
or
hire a timber frame designer (like me),
or
review "Hip and Valley Framing" and the Hawkindales on this web site at
http://www.tfguild.org/tool2.html, which includes a downloadable spreadsheet for automation of your calculations.