θ is the angle between a and b in the plane containing them (hence, it is between 0° and 180°), ‖a‖ and ‖b‖ are the magnitudes of vectors a and b, n is a unit vector perpendicular to the plane containing a and b, with direction such that the ordered set (a, b, n) is positively oriented.
θ is the angle between a and b in the plane containing them (hence, it is between 0° and 180°) ‖a‖ and ‖b‖ are the magnitudes of vectors a and b, n is a unit vector perpendicular to the plane containing a and b with direction such that the ordered set (a, b, n) is positively oriented