Hi Larry,

re:
> Yes, the circular arcs will be the most common sort of die to simulate.

The case of tangent between 2 circles can be solved directly.

A really good source for this kind of thing is the book "A Programmer's Geometry", which can be accessed on archive.org here:
https://archive.org/details/AProgrammersGeometry

See section 2.6 "Tangents between 2 circles".

- Michael