题解 | #计算三角形的周长和面积#

import java.util.Scanner;
//海伦公式求三角形面积,忘记了的上网查
// 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 sc = new Scanner(System.in);
        double a = sc.nextDouble();
        double b = sc.nextDouble();
        double c = sc.nextDouble();
        double circumference = a + b + c;
        double p =  (a + b + c) / 2;
        double area = Math.sqrt(p * (p - a) * (p - b) * (p - c));
        System.out.printf("circumference=%.2f area=%.2f", circumference, area);
    }
}