This function finds the distance between two points. '''Parameters:''' * double x1 - x coordinate of first point. * double y1 - y coordinate of first point. * double z1 - z coordinate of first point. * double x2 - x coordinate of second point. * double y2 - y coordinate of second point. * double z2 - z coordinate of second point. '''Responds:''' * TBD '''Reports:''' * TBD '''Example:''' * User sends: "fd 0 0 0 3 4 12" * answer is 13