Further Applications of Dot and Cross Product Q1

The equation of line \({{l}_{1}}\) is given by \(\mathrm{r}=\left( \begin{matrix} 2 \\ 1 \\ 0 \end{matrix} \right)+\lambda \left( \begin{matrix} 1 \\ 2 \\ -1 \end{matrix} \right)\) . Another line \({{l}_{2}}\) is parallel to the line \({{l}_{1}}\) and passes through \(A\left( 3,1,-2 \right)\). Find the exact distance between the lines \({{l}_{1}}\) and \({{l}_{2}}\).