Introductory Vector Equation Illustrated by a Moving River -- Picture Included 1. The problem statement, all variables and given/known data A swimmer wants to cross a river, from point A to point B, as shown in the figure. The distance (from A to C) is 100 , the distance (from C to B) is 75 , and the speed of the current in the river is 5 . Suppose that the swimmer's velocity relative to the water makes an angle of with the line from A to C, as indicated in the figure. To swim directly from A to B, what speed , relative to the water, should the swimmer have? 2. Relevant equations A to B2=1002+752 A to B= 125 meters That's about all I really know how to do. For some reason I can't think of a way to go about solving this problem. Any ideas?