Java Program To Calculate Area Of Circle

import java.util.Scanner;
public class demo1 
{
   public static void main(String args[]) 
    {         
      Scanner input= new Scanner(System.in);        
         System.out.println("Enter the radius:");
         double r= input.nextDouble();
         double  area=(22*r*r)/7 ;
         System.out.println("Area of Circle is: " + area);      
   }
}