\({S_{ABC}} = \left| {\left[ {\overrightarrow {AB} ,\overrightarrow {AC} } \right]} \right|\)      

\({S_{ABC}} = \dfrac{1}{2}\left| {\left[ {\overrightarrow {AB} ,\overrightarrow {AC} } \right]} \right|\)         

\({S_{ABC}} = \dfrac{1}{4}\left| {\left[ {\overrightarrow {AB} ,\overrightarrow {AC} } \right]} \right|\)        

\({S_{ABC}} = \dfrac{1}{6}\left| {\left[ {\overrightarrow {AB} ,\overrightarrow {AC} } \right]} \right|\)