Snellius–Pothenot problem

I don't know if anyone is familiar with this kind of exercise, but I'd like to post this here. It's an exercise on determing the coördinates of an unknown point, using coördinates of- and angles between kown points (goniometry).(http://en.wikipedia.org/wiki/Snellius%E ... ot_problem)

I've been searching the internet for examples, but I couldn't find a well-worked example anywhere... I know this might take some time and work, but if someone solves this, they'd really help me a lot!

So, I was given this problem:

A theodolite is placed in point D. From this point D, the following angles are measured: to point A (398.2315 gon), to point B (43.9187 gon) and to point C (70.9120 gon)*. The planimetric coördinates of A, B and C are: XA: 10000.0, YA: 18000.0, XB: 15000.0, YB: 23000.0, XC: 20000.0, YC: 28000.0. **(180 degrees = 200 gon)*

Now first make a sketch of this problem, then calculate the coördinates of point D and the distance between points B and D.

Thanks a lot!