题解 2768: 与圆相关的计算-java

解题思路:

注意事项:

参考代码:```import java.util.Scanner;

public class Main {
   public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
       double r = sc.nextDouble();
double d=2*r;
double c=2*3.14159*r;
double s=3.14159*r*r;
       System.out.printf("%.4f %.4f %.4f",d,c,s);

   }
}```