Hello, here is a couple of example problems I'm not sure how to do, if someone could please explain how to do it I would greatly appreciate it! Subtraction: "A river flows at 0.8 m/s. If a boat moves across the water at 2m/s at what angle should it point so that it moves straight across the river perpendicular to the bank?" Addition: "A plane flies at a bearing of 270 degrees at 200km/h through a cross wind blowing from a bearing of 360 degrees at 80km/h. What is the plane's velocity over the ground?" Thank you!