Measure the angle between vectors in a plane.

Input parameters:

1. Va → First vector for angle measurement.
2. Vb → Second vector for angle measurement.
3. Pl → Plane in which to measure angles.

Output parameters:

1. CW → Angle from A to B in the clockwise direction on the plane.
2. AW → Angle from B to A in the anti-clockwise direction on the plane.