Program to do circle operations in JAVA

import java.text.*;

public class Circle


{

  public static void main (String[] args)

  {

    // create decimal format

    DecimalFormat DF = new DecimalFormat ("0.00000");

    // Radius is the radius of the circle
    // Diam is diameter
    // Circum is circumference
    // Area is area of circle

    double Radius = 6.75;
    double Diam;
    double Circum;
    double Area;

    // PI is constant 3.14159

    final double PI = 3.14159;

    // calculate diameter

    Diam = 2 * Radius;

    // calculate circumference

    Circum = PI * Diam;

    // calculate area

    Area = PI * Radius * Radius;

    // display intro message

    System.out.println("This program calculates Diameter, Circumference, and Area of a circle");

    // display the result

    System.out.println("Radius constant = " + DF.format(Radius));
    System.out.println("Diameter = " + DF.format(Diam));
    System.out.println("Circumference = " + DF.format(Circum));
    System.out.println("Area = " + DF.format(Area));

    // display end message

    System.out.println("End of program");

  }

}