I think this may be what your after:
http://hnsa.org/doc/attack/#platexvi
Its a derivative of the Sine rule by the looks.
IE: A/Sin(a) = B/Sin(b)
B = A*Sin(b)/Sin(a)
Of course the example is for a collision course IE: No change of AOB.
The whole article from which this plate is from will most likely provide you the remaining data.