# Proportional Symbol

Symbol Format Data
Code Point
U+221D
TeX
\propto
SVG

## Usage

The proportional symbol indicates that one expression changes in proportion to the other. For example, in the definition of an angle measured in radians, it can be said that the radius is proportional to arc length.

In plain language, this means that as the radius of the circle grows, the arc-length described by an angle also grows proportionally.