# π > The mathematical constant [π][pi].
## Usage ```javascript var PI = require( '@stdlib/constants/float64/pi' ); ``` #### PI The mathematical constant [π][pi]. ```javascript var bool = ( PI === 3.141592653589793 ); // returns true ```
## Examples ```javascript var PI = require( '@stdlib/constants/float64/pi' ); console.log( PI ); // => 3.141592653589793 ```