---
tag: 073JKP99K2
kind: concept
name: Tangent plane and normal vector of a surface
aliases: [surface-normal]
msc: [53A05]
uses: [0ZG9QF40HE]
sources:
  - url: https://en.wikipedia.org/wiki/Normal_(geometry)
    locator: Normal to general surfaces in 3D space
---

## Summary

The tangent plane of a [[surface|0ZG9QF40HE]] at a point is the plane that best approximates the surface near the point.
A normal vector is a nonzero vector perpendicular to the tangent plane.