Relative to an origin O, the position vectors of the points A, B, C and D, shown in the diagram, are given by

\(\overrightarrow{OA} = \begin{pmatrix} -1 \\ 3 \\ -4 \end{pmatrix}, \overrightarrow{OB} = \begin{pmatrix} 2 \\ -3 \\ 5 \end{pmatrix}, \overrightarrow{OC} = \begin{pmatrix} 4 \\ -2 \\ 5 \end{pmatrix} \text{ and } \overrightarrow{OD} = \begin{pmatrix} 2 \\ 2 \\ -1 \end{pmatrix}.\)

1. Show that AB is perpendicular to BC.
2. Show that ABCD is a trapezium.
3. Find the area of ABCD, giving your answer correct to 2 decimal places.