Using the math method, I used the pythagorean theorem to find the length in NM of the direct route, then Cosine to find one of the unknown angles. This angle was used to find the 3rd angle (180 degrees in total) and this added or subtracted the recripocal of the radial to find the direct heading. If someone has a shortcut I'd appreciate it, but the above was the only method I could come up with.