ok, lets say we have 2 guys, for simplicity we will say they are a [10,20,0] for the first guy's pos, and [15,30,0] for the second, and we want to know what the actual distance is between them.
so first we do:
15 - 10 = 5 (one side or
leg as it is called in geometry and stuff)
30 - 20 = 10 (other leg)
then 5 squared, or 52,or 5^2, is 25 (5*5)
and 10 squared is 100
add then together 100 + 25 = 125 ___
and do the square root (calculator) \/125 = 11.18m
so heres a problem for you to do if you want:
guy1's pos = [50,25,0]
guy2's pos = [73,42,0]
find the distance between them
EDIT: sorry ofpfreak, but penguinman is askin, and you don't seem to have any question that need answering