word problem with boats and directions

[88m]

Two sailboats leave a harbor in the Bahamas at the same time. The first sails at 20 mph in a direction 330°. The second sails at 34 mph in a direction 220°. Assuming that both boats maintain speed and heading, after 2 hours, how far apart are the boats?

89.9 miles
70.5 miles
58.5 miles
95.9 miles

my instructor is being a hard @$$ and is not helping me here. i don't know the right formula and how to insert the values into it. SO please someone get me started.

 

[galactus]

Use the law of cosines. The angle is 110 degrees and you can easily calculate the two side lengths by using d=rt.

 

[stapel]

my instructor is being a hard @$$ and is not helping me here.

You're blaming the instructor for your having forgotten trigonometry...? :shock:

You've at least figured out the angle between the boats' paths, drawn the picture, and found the distances they've travelled, right? And you noted that you need the length of the side opposite the given angle, right? So what's left, other than one of the Laws you memorized back in trigonometry...?

Eliz.