Java Math.PI is a constant in the Java Math class that represents the mathematical constant π (pi), the ratio of the circumference of a circle to its diameter. It is used in mathematical and geometric calculations, particularly when working with circles, angles, or trigonometric functions. Introduced in Java 1995 with Java 1.0, PI is a key constant for scientific computing and engineering applications in Java.

https://docs.oracle.com/javase/8/docs/api/java/lang/Math.html