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$\begin{array}{1 1} d.c.=(\frac{1}{\sqrt3},\frac{1}{\sqrt3},\frac{1}{\sqrt3})\; distance =1units \\d.c.=(1,1,1)\; distance =\frac{1}{\sqrt3}\;units \\d.c.=(\frac{1}{\sqrt3},\frac{1}{\sqrt3},-\frac{1}{\sqrt3}) distance\; =\frac{1}{\sqrt3}\;units \\ d.c.=(\frac{1}{\sqrt3},\frac{1}{\sqrt3},\frac{1}{\sqrt3})\; distance \;=\frac{1}{\sqrt3}units \end{array} $