Program Keliling Lingkaran

package kelilinglingkaran;


public class Main {
    public static void main(String[] args) {

        double phi=3.14;
        double r = 20;
        double keliling=40;

        keliling =2*phi*r;

        System.out.println("===================");
        System.out.println("Keliling 40 =+Keliling");
        System.out.println("===================");
    }

}