For the first problem you've left out some critical data - such as the speed of the two boats - so it's impossible to answer as written.
For the 2nd you know that the 3 sides of the triangle are lengths 7, 8, and 9 - do you see what that is? Now apply the law of cosines:
You have values for A, B and C, so solve for and hence the angle 'c'. Repeat for angle 'b', and angle 'a' is 180 degrees - c - b.