Thanks for the clarification above - my terminology might not be up to scratch.
Of three points (A,B and C) on the earth's surface, forming a triangle (sides 999nm, 349nm, 745nm) I want to find the point that is equidistant from A, B, and C.
This point would naturally need to be on the earth's surface as I want to leave fuel there! Accuracy is only required down to a few nm which is just as well as there are issues regarding the 14000' height difference between B and A, and the assumption that the earth is spherical.
Enicalyth, thanks for the pointers - will check when I get back in tonight.
