The cross product is only defined in three dimensional space and is denoted . The cross product is defined as a vector that is perpendicular (orthogonal) to bot and with a direction given by the right-hand rule and a magnitude equal to the area of the parallelogram that the vectors span.
Where is the angle between and , is the Euclideannorm and is the unit vector that is perpendicular to both vector, in the direction of the right-hand rule.