Holy Grail for Roof Framing Geometry

There are no decimal points in Euclidean Geometry using a straightedge and Compass.

I deciphered what Euclid was drawing on the plaster tablet in 200 BC.  

The Euclidean Geometry for the Devers-canted hip rafter head cuts. 

Using the roof surface angles, the profile rafter slope angle and the valley rafter sleeper angle you can draw out the Devers hip rafter head cut and foot cut angles. As well as the jack rafter and purlin rafter head cuts.