Square Root
Part of Math Symbols
On Windows, hold Alt and type 251 on the numeric keypad to insert square root.
- Alt code
- Alt+251
- HTML entity
- √
- Unicode
- U+221A
About this symbol
The radical sign for square roots first appeared in print in 1525, in Die Coss, an algebra book by the German mathematician Christoph Rudolff. It is often said to come from a small letter r, for radix, Latin for root. The bar that extends over the number, the vinculum, was added later by René Descartes.
Unicode facts
- Official name
- SQUARE ROOT
- Also called
- Radical sign
- Type
- Maths symbol
- Unicode block
- Mathematical Operators
- Unicode group
- Operators
- Added in
- Unicode 1.1 (1993)
Click the symbol or any value at the top of the page to copy it. See the full Math Symbols chart for related characters.