bowtech-1, the pythagorean theory does work, its just a pain to remember and calculate while your staring at a nice buck. If you set your stand at 25' high and if you know the distance to the animal from the base of the tree is 20 yds then you would aim as if the animal is 15 yds away. Likeeveryone said, just practice. Although, it does matter in rifle or muzzleloading when taking steep uphill or downhill shots at long distances.