Layover Valley Rafter Hexenschnitt #1

While studying the: The Layover Valley Sleeper with Witch Cut
Die Kehlbohle mit Hexenschnitt

In the book
Das neue Buch vom alten Wissen der Schiftung
The new book on the ancient knowledge Schiftung
The new book on the ancient knowledge Roof Framing
The new book on the ancient knowledge Roof Framing Geometry

by Bernd Küppers

I realized I need to backtrack and draw out the roof surface averaging lines used to determine the ground plan roof framing geometry, the intersection of lines of the individual roof surfaces. I could have cheated and used my RafterTools Calculator app for the plan angles of the three different roof slopes on the task model, but then it would have defeated the purpose of studying the Shiftung geometric method for the witches cut of the layover valley sleeper. Just a refresher in developing the plan angles using geometry only.

Dachausmittlung
Roof Design
from
Intersecting Roof Surfaces

Optional Roof Design:

Here's the roof surface design for the PIA equal overhang. 

Here's the plate heights for the PIA equal overhang.