Yes these are the coordinates. I'm sure they need to be converted to UTM (universal Trans Mercator) to use in an equation. I just need the correct equation to use. There has to be a basic geometry equation that doesn't need sine, cosine etc. UTM Coordinates are as follows.

A = 13s E 509074 N 4325872

B = 13s E 511081 N 4328150

C = 13s E 512236 N 4322782

can anyone give me an equation to work with? I'm assuming I'll have to do the math twice. Once for the easting and then another for the northing.

No trig? How else would you do it? I would be interested in knowing.

I was a surveyor for years and sine and cosine is what is used to inverse, traverse, etc.

What does the 13s stand for?

Using basic trig I found from A to B:

Azimuth of 41.381 degrees and 3036 feet or whatever unit you're using.

A to C as an azimuth of 134.34 degrees and 4421.12 feet.

B to C is an azimuth of 167.86 degrees and 5490.85 feet

I am sorry, I am not familiar with UTM. Perhaps do a Google search.