Boat A travels at 10km/hr on a course of 280 degrees (this is `10^@` north of due west.)
Boat B travels at 13 km/hr on a course of 165 degrees (this is `15^@` east of south.)
After 2 hours boat A has travelled 20km, and boat B has travelled 26km.
The angle between the boats is `280^@-165^@=115^@` .
Draw a triangle with one side 20, one side 26, and the included angle `115^@` . We can use the Law of Cosines to ind the third side, which is the distance between the boats.
The distance between the boats is approximately 38.93km