Problem 3.
The three vertices of a triangle are located at A(6, -1, 2), B(-2, 3, -4), C(-3, 1, 5),
determined in Cartesian coordinates.
a) Find the cross product of the vectors \overrightarrow{R_{AB}} and \overrightarrow{R_{AC}}
b) Find the unit vector perpendicular to the plane of the triangle ABC
c) Find the area of the triangle ABC