The vertices of a triangle are A(1,2,3), B(4,−1,2) and C(−2,3,0).
a. (i) Write the vectors representing the two sides that meet at A.
b. (ii) Compute the angle ∠BAC of the triangle, correct to the nearest degree.
c. (iii) Using your result from part (ii), classify △ABC as right-angled, acute-angled, or obtuse-angled at A.