ORIGINAL: OHBowhunter
Your math formula is correct if you are building a roof. What they are trieng to tell you is the only distance you need is from the base of your tree to the target. Forget about the extra distance from the angle. The downward projection makes up for that.
I disagree. Heres a quick copy from Bob Humphrey, a writer for Game and Fish Mag. He is a noted archery expert.
ELEVATION
It's probably fair to say most archers hunt from tree stands. I'd venture to guess that a considerable number of them don't practice from elevated stands. That's a big mistake. The trajectory of an arrow fired horizontally is quite different from one fired at a steep downward angle. On a downward shot, the effect of gravity is amplified, usually resulting in an overshot.
What is the original poster doing????? He is dead on target on the ground, but from a stand he is high.... The cause? It's an overshot.