Vector Algebra

If \(\overrightarrow a ,\overrightarrow b ,\overrightarrow c\) are three non-zero vectors and \(\widehat n\) is a unit vector perpendicular to \(\overrightarrow c\) such that \(\overrightarrow a = \alpha \overrightarrow b - \widehat n,(\alpha \ne 0)\) and \(\overrightarrow b \,.\overrightarrow c = 12\), then \(\left| {\overrightarrow c \times (\overrightarrow a \times \overrightarrow b )} \right|\) is equal to :