The three dimensional coordinate system provides the three physical dimensions of space ÃƒÂ¢Ã¢â€šÂ¬Ã¢â‚¬Â height, width, and length.
The coordinates in a three dimensional system are of the form (x,y,z). As an example, two points are plotted in this system P(3,0,5) and Q(ÃƒÂ¢Ã‹â€ Ã¢â‚¬â„¢5,ÃƒÂ¢Ã‹â€ Ã¢â‚¬â„¢5,7). The axes are depicted in a world-coordinates orientation with the z-axis pointing up.
The x-, y-, and z-coordinates of a point can also be taken as the distances from the yz-plane, xz-plane, and xy-plane respectively.
long live wikipedia