PRECALC HELP
posted by JOHN on .
Two boats leave the same port at the same time. One travels at a speed of 31 mi/h in the direction N 50° E and the other travels at a speed of 20 mi/h in a direction S 70° E (see the figure). How far apart are the two boats after one hour? (Round your answer to the nearest mile.)

convert to rectangular form and subtract one from the other.
convert back to polar to get the distance.