The short version:

1. Took a bearing on Landmark from postion A
2. Walked from A to B
3. Took another bearning on Landmark from position B
4. Use Law of Sines to determine all angles and side lengths for LAB triangle.
5. Using info from #4, bearing & distance from Landmark to Home, AND Law of Cosines to determine distance from B to Home.
6. Use Law of Sines to find all angles & sides for LBH triangle. This gives bearing from B to Home.

This couldn't have been done without both laws.

I honestly can't imagine doing this in the field without a decent piece of paper and a scientific calculator.