Two ships have a harbor entrance at the same time. the first ship is traveling at a constant 16 mph, while the second is traveling at a constant 20 mph. if the angle between the course is 169°, how far apart are they after 2 hours? (round answer to nearest whole number.)

So hmm check the picture below

both ships leave at the same time, one is going 16mph, the other 20mph, 2hrs later on the road

at 16mph well, 2hrs is just 16+16, or 32 miles away
20mph for 2hrs, is 20+20, or 40 miles away

using the law of cosines  

again, recall, the angle is in degrees, so, when taking the cosine, make sure your calculator is in Degree mode

It’s c. i’m almost sure