[Edu-sig] OT: calculating dodeca icosa solid assembly angles

[Jason Cunliffe]

I need to make some regular dodecahedrons and icossahedrons for 
sculptural project.
Want to set up some jigs for mitre saw and saw table in my shop, to help 
me cut wood and plastic modules for making several prototypes at 
different sizes and and as for making casting molds etc. Repeat 
precision is the name of the game.

Can anyone please point me to  good info for angles and layout specs to 
do this?
The most important data I am missing is the solid bevel angle each face 
should have for assembling dodecas and icosas respectively.

Bonus request is if you can show me the [pythonic] math for calculating 
this simple angle.

Thanks very much any suggestions, links etc.
Jason