Q3. Points A, B and C have coordinates (3,1, 8), (2, 5, 2) and (2,3,-9) respectively.
(a) Find vector \overrightarrow{AB} and \overrightarrow{AC};
(b) Find \overrightarrow{AB} \times \overrightarrow{AC} and hence find the area of the triangle ABC.
(10 marks)
(10 marks)