For points plotted in a 3 dimensional space or coordinate, you would be given three values which would represent the x direction, the y direction and the z direction. Given two points plotted on a 3 dimensional coordinate, (x1, y1, z1) and (x2, y2, z2), like for points that are being plotted in a 2 dimensional coordinate the distance would be calculated as:
distance = √((x2 - x1)² + (y2 - y1)² + (z2 - z1)²)
For instance, we have point (1,1,1) and point (2,2,2), the distance of these points would be
distance = √( (2 - 1)² + (2 - 1)² + (2 - 1)² )
distance = 1.73 units