具有数学功能的圆形面积计算器

import java.util.Scanner;


public class CircleAreaApp
/**来自 
 n o w j a   v  a . c o m - 时  代  Java**/

{


  static Scanner sc = new Scanner(System.in);


  public static void main(String[] args)

  {

    System.out.println("Welcome to the circle area calculator.");

    System.out.print("Enter the radius of your circle: ");

    double r = sc.nextDouble();//时代Java公众号 - nowjava.com 提 供

    double area = Math.PI * (r * r);

    System.out.println("The area is " + area);

  }


}