java求圆的面积和周长

        import java.util.Scanner;

public class Fuxi1 {
    public static void main(String [] args ){
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入圆的半径");
        double  f=sc.nextDouble();
        double c=3.14;
        double  a=2*c*f;
        double  d =c*f*f;
        System.out.println("半径："+f);
        System.out.println("周长是："+a);
        System.out.println("圆的面积："+d);
    }
}