1. The problem statement, all variables and given/known data Find the normal force acting on a mass of 5kg on an incline plane of 30 degrees. 2. Relevant equations Fn = mgsin30 or mgcos30 ? 3. The attempt at a solution I'm not sure if I use sin or cos when finding the normal force on an incline. I have trouble visualizing the angle perpendicular to the plane and moving the angles around.