...by A x B, is a vector C such that the magnitude of C is the product of the magnitudes of A and B and the sine of the angle between them. The direction of the vector Cis perpendicular to both A and B such that A, B and C form a right handed system. That is, if we say...

...-MJV- bd', be' -cb') ; the product-line is perpendicular to the plane of the factors; its length is the product of their lengths multiplied by the sine of the angle between them : and the real part of the product, with its sign changed, is the same product of the lengths of the...