Trong không gian $Oxyz$ cho hai vectơ $\overrightarrow{u}$ và $\overrightarrow{v}$, khi đó $\left| \left[ \overrightarrow{u},\overrightarrow{v} \right] \right|$ bằng
$\left| \overrightarrow{u} \right|.\left| \overrightarrow{v} \right|.\sin \left( \overrightarrow{u},\overrightarrow{v} \right).$
$\left| \overrightarrow{u} \right|.\left| \overrightarrow{v} \right|.cos\left( \overrightarrow{u},\overrightarrow{v} \right).$
$\overrightarrow{u}.\overrightarrow{v}.cos\left( \overrightarrow{u},\overrightarrow{v} \right).$
$\overrightarrow{u}.\overrightarrow{v}.\sin \left( \overrightarrow{u},\overrightarrow{v} \right).$