Normal (geometry)
in geometry, an object that is perpendicular to a given object, vector perpendicular to a curve or surface
In geometry, a normal is an object (e.g. a line, ray, or vector) that is perpendicular to a given object. For example, the normal line to a plane curve at a given point is the infinite straight line perpendicular to the tangent line to the curve at the point.
A normal vector is a vector perpendicular to a given object at a particular point.
A normal vector of length one is called a unit normal vector or normal direction. A curvature vector is a normal vector whose length is the curvature of the object.
Multiplying a normal vector by −1 results in the opposite vector, which may be used for indicating sides (e.g., interior or exterior) or orientation (e.g., clockwise vs. counterclockwise, right handed vs. left handed).
In three-dimensional space, a surface normal, or simply normal, to a surface at point P is a vector perpendicular to the tangent plane of the surface at P. The vector field of normal directions to a surface is known as Gauss map.
“Normal (geometry)” enters the record as in geometry, an object that is perpendicular to a given object, vector perpendicular to a curve or surface. Crown Archives preserves that source wording while asking what Normal, geometry and object can confirm, complicate or overturn.
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Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Apr 8, 2026. The linked authority identifier is Q273176. None of the 0 selected statements returned an explicit reference.
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This entry incorporates text from “Normal (geometry)” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.