Grade 12 math: vectors as forces?

two tugs are towing a ship. the smaller tug is 15 degrees off the port bow, and the larger tug is 20 degrees off the starboard bow. the larger tug pulls twice as hard as the smaller tug. in what direction will the ship move?

Larger tug force = 2*cos20 forward + 2*sin20 to the right (starboard) 
Smaller tug force = 1*cos15 forward + 1*sin15 to the left (port) 

Resultant force forward = 2*cos20 + 1*cos15 = 2.8453 (4dp) 
Resultant force to right = 2*sin20 - 1*sin15 = 0.4252 (4dp) 

Angle of resultant force = arctan(0.4252 / 2.8453) = arctan(0.1494) = 8.5 degrees

Gas will most likely  fill the container