A look at the theory behind cognate tetrahedra or kernels modeling the compound angles in a complex Hip-Valley roof.
Cyclic arrangements of angles within the tetrahdron are analysed,
and applied to generating angles in the different kernels found in a Hip/Valley roof,
including Rectangular or Interlocking kernels.
The two Cognate Kernels worksheets, found under
puts the theory to work and generates angle formulas.