Two ships leave San Francisco at the same time. One travles 40 degrees W of N at the speed of 20 knots. The other travels 10 degrees W of south at a speed of 15 knots. How far apart are they after 11 hours?

Answer 1

The first one will have travelled 220 nautical miles, the second one 165 n miles.
the angle between their paths is 130º

so dist^2 = 220^2 + 165^2 - 2(220)(165)cos130
= ..
= ..

I am sure you can do the arithmetic.