Editing Normal (geometry) (section)

===Orientation===
[[Image:Surface normals.svg|right|thumb|300px|A vector field of normals to a surface]]
The normal to a (hyper)surface is usually scaled to have [[Unit vector|unit length]], but it does not have a unique direction, since its opposite is also a unit normal. For a surface which is the [[Boundary (topology)|topological boundary]] of a set in three dimensions, one can distinguish between two '''normal orientations''', the '''inward-pointing normal''' and '''outer-pointing normal'''. For an [[Orientability|oriented surface]], the normal is usually determined by the [[right-hand rule]] or its analog in higher dimensions.

If the normal is constructed as the cross product of tangent vectors (as described in the text above), it is a [[pseudovector]].