This corresponds to the two possible orientations of the coordinate system.

You won't have to worry anymore about there being two possible orientations for each one.

It interacted with the many possible intellectual orientations available to Indian thinkers around the 8th century.

The correct procedure is to average over all possible orientations of the intersecting plane.

Every immersed curve in the plane admits two possible orientations.

Minimising the fit involves starting with all possible orientations for a triplet.

Being hexagonal, there are six possible orientations for placing each tile.

Ideally, every possible crystalline orientation is represented very equally in a powdered sample.

The magazine well is fairly loose, allowing the magazine a wide range of possible orientations.

However, the middle layer has two possible orientations for each position, increasing the number of positions by a factor of 2.