---
tag: 0WQJJCCTC8
kind: concept
name: Normal vector
aliases: [normal]
msc: [51N20]
sources:
  - url: https://en.wikipedia.org/wiki/Normal_(geometry)
    locator: lead section
same_as:
  wikidata: Q273176
  wikipedia: Normal (geometry)
---

## Summary

A normal vector of a line, a plane or a surface is a nonzero vector that is perpendicular to it. For a curved surface, a normal vector at a point is perpendicular to the tangent plane at that point.