5. The square-based pyramid \(P\) has vertices \(A , B , C , D\) and \(E\). The position vectors of \(A , B , C\) and \(D\) are \(\mathbf { a , b , c }\) and \(\mathbf { d }\) respectively where $$\mathbf { a } = \left( \begin{array} { r } - 2
3
- 1 \end{array} \right) , \quad \mathbf { b } = \left( \begin{array} { r } 5
8
- 6 \end{array} \right) , \quad \mathbf { c } = \left( \begin{array} { l } 2
5
3 \end{array} \right) , \quad \mathbf { d } = \left( \begin{array} { l }