1. Trying to understand how to work a given angle into an answer in projectile motion problems. 2. ΔX=ViTf+1/2ATf^2 R=2vi^2sinθcosθ/g 3. Well, I know if you're given say 45° then you would use sin for vertical and cos for horizontal. But beyond that, what are you supposed to do with an angle when given one. ALSO: For the first equation, do you substitute Vi for Visinθ or Vicosθ?