题解 | #计算三角形的周长和面积#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        double a,b ,c;
        do{
         a = in.nextDouble();
          b = in.nextDouble();
          c = in.nextDouble();
          if(a+b>c || a+c>b || b+c>a){
            break;
          }
        }while(true);
      double circumference=a+b+c;
      double p = (a+b+c)/2.0;
      double area = Math.sqrt(p*(p-a)*(p-b)*(p-c));
      
      System.out.printf("circumference=%.2f area=%.2f",circumference,area);
    }
}