Four Bearing method into a formula/equation?

[Dignan]

So I need some advice from the trig/geometry brains here.

I have been practicing the 4 bearings method a lot lately and want to develop a quick tool to use to calculate course of a target. I love the Hydrophone tracker tool by Gutted but it isn't available in an app and I don't want to alt-tab out of the game to use it.

So my next option is to use a trig/geo app that allows me to build a formula for the 4 bearings method that I can just plug in values. Do any of the "10 pound brains" on this forum know what the equation for the four bearings method would look like? For example, if your values are as follows;

A= bearing 1
B= bearing 2
C= bearing 3
T= time intervals between bearing readings

What would the formula/equation look like on paper that would spit out a target's course? I realize I still need to take the 4th bearing from a different location to triangulate a location but 3 bearings into a formula would be a good start.