A plane \(\Pi\) has an equation of \(\mathbf{r}\cdot\mathbf{n}=k\).
If the origin is on the plane explain how the value of \(k\) could be determined and state its value.
State the unit vectors of the normal of \(x-y\), \(y-z\) and \(x-z\) planes. Thus, find the equations of each plane.
Show that the shortest distance of plane \(\Pi\) to the origin is \(\frac{|k|}{|\mathbf{n}|}\).