At 9am, a certain boat left a port in the direction of 50° east of north and maintains a speed of 90kph. At that same time, another boat left the same port in the direction of 30° east of south. How far apart were the two boats, two hours after they left the port?
distance = speed * time
If the 2nd boat also goes at 90km/hr, then
using the law of cosines, the distance z is
z^2 = 180^2 + 180^2 - 2*180*180 cos100°