c = a × b. The result of cross product of vectors "a" and "b" is vector "c". Magnitude "c". c = |a||b|sinα. α - angle between vectors "a" and "b". |a|, |b|, |c| - magnitude of vectors. Direction "c" is at the same time perpendicular to "a" and "b". We find it on the base corkscrew rule. Turn corkscrew from "a" to "b".