ASL STEM

Definition

Part of the torque calculation is the determination of direction. The direction is perpendicular to both the radius from the axis and to the force. It is conventional to choose it in the right hand rule direction along the axis of rotation.

Source: http://hyperphysics.phy-astr.gsu.edu/hbase/tord.html

Example

Another definition: The rule which determines the orientation of the cross product u x v. The right-hand rule states that the orientation of the vectors' cross product is determined by placing u and v tail-to-tail, flattening the right hand, extending it in the direction of u, and then curling the fingers in the direction that the angle v makes with u. The thumb then points in the direction of u x v. (http://mathworld.wolfram.com)