---
tag: 0T7DX8NY1X
kind: concept
name: Tangent line to a circle
msc: [51M04]
sources:
  - url: https://en.wikipedia.org/wiki/Tangent_lines_to_circles
    locator: lead section
same_as:
  wikidata: Q647040
  wikipedia: Tangent lines to circles
---

## Summary

A tangent line to a circle is a line that meets the circle in exactly one point, the point of tangency. It does not enter the inside of the circle, and it is perpendicular to the radius at the point of tangency.