Question 144643
You did it right, but the angle between the paths is 80 degs, not 86 or 85. That makes the distance 43.3325 km.
Then, use the law of sines to determine the angle from boat A to B, which is 34.623 degs.  Looking from boat A back to the marina would be the recip or 65 degs, or 245 degs.  Subtract the 34.623 from that, giving 211.377 degs.