Question

Two boats start out from the same dock traveling at 9 mph and 12 mph respectively. The boats travel in slightly different directions and after 20 minutes are 2 miles apart. What is the angle that is formed by the paths of the two boats? I don't know how to set this up please help and explain!

Answer 1

20 min = 1/3 hour so
boat a goes 3 miles and boat b goes 4 miles

sides of triangle are 2, 3 and 4 miles
use law of cosines to find angle opposite the 2 mile side.

Answer 2

Thank you so much!