$${\mathtt{6}}{\mathtt{\,\times\,}}{{\mathtt{a}}}^{{\mathtt{2}}} = {\mathtt{726}}\left[{{cm}}^{{\mathtt{2}}}\right] \Rightarrow \left\{ \begin{array}{l}{\mathtt{a}} = {\mathtt{\,-\,}}\left({\mathtt{11}}{\mathtt{\,\times\,}}{\mathtt{cm}}\right)\\
{\mathtt{a}} = {\mathtt{11}}{\mathtt{\,\times\,}}{\mathtt{cm}}\\
\end{array} \right\}$$
$${\mathtt{6}}{\mathtt{\,\times\,}}{{\mathtt{a}}}^{{\mathtt{2}}} = {\mathtt{726}}\left[{{cm}}^{{\mathtt{2}}}\right] \Rightarrow \left\{ \begin{array}{l}{\mathtt{a}} = {\mathtt{\,-\,}}\left({\mathtt{11}}{\mathtt{\,\times\,}}{\mathtt{cm}}\right)\\
{\mathtt{a}} = {\mathtt{11}}{\mathtt{\,\times\,}}{\mathtt{cm}}\\
\end{array} \right\}$$