So I have a boat going across a river (y-direction, north) 400m wide. I am trying to hit a target 75m in the positive x direction on the opposite side of the river. My boat will travel a velocity v. The river will provide a constant velocity of +0.5 (east) I am trying to find the angle a, north of west to point my boat. hope that all makes sense. so far I have: y = vt or t = y/v t = 400 / v*sin(a) x = vt 75 = [0.5 - cos(a)] * t then I plugged in t 75 = 200/[v*sin(a)] - [400*v*cos(a)]/[v*sin(a)] I cant seem to solve this. Am I doing this the right way? I was thinking I need another function and I remember having to use sin(a)^2 + cos(b)^2 = 1 for something like this a while back. And if I do, how do I? Do I just solve the first two equations for sin and cos and then plug the equations in to the third, expand them, then solve another for t and then plug it in and simplify? any help would be greatly appreciated.