Question: how to find the distance between two points with 3 coordinates?
Answer: d(P1,P2) = (x2 x1)2 + (y2 y1)2 + (z2 z1)2. This can be proved by repeated application of the Pythagorean Theorem. Example The distance between P1 = (2,3,1) and P2 = (8,5,0) is d(P1,P2) = (8 2)2 + (5 3)2 + (0 1)2 = 36 + 64 + 1 = 101 10.05.