1. The problem statement, all variables and given/known data A boat that can travel at 4.0km/h in still water crosses a river with a current of 2.0 km/h. At what angle must the boat be pointed upstream (that is, relative to its actual path) to go straight across the river? 2. Relevant equations No equations were given but it seems like a simple trig problem, just can't get the right answer 3. The attempt at a solution My first attempt i used inverse tan theta (4/2) and got an angle of 63 My second attempt i used inverse cos theta (2/4) and got an angle of 60 the actual answer is 30. Either there is a very big step i'm missing or i've drawn something horribly wrong.