*cough, cough* Man, you're getting it everywhere. Let the crows have run of the field for a second and follow how the conversation goes with a competent GM.
DM: "Okay, ranger, you can attack. Go ahead."
Ranger: "I attack, uh, goblin #4."
DM: "Roll."
Ranger: "Wait, how far away is the goblin?"
DM: "About 80 feet, counting the distance you're shooting up the tree."
Ranger: "Great, that's inside one increment! *rolls*"
As with every single other thing in an RPG session that isn't represented with miniatures - city streets, non-hostile NPCs, weather, terrain, magical effects, the results of damaging blows - you describe it to the players using words.
I'm a little concerned that it's such a mind-boggling thing for you.