#include<stdio.h>
#include<math.h>
void main()
{
float a, b, c, p, s;
printf("请输入三角形三条边长:\n");
scanf("%f,%f,%f", &a, &b, &c);
p = (a + b + c) / 2;
s = sqrt(p * (p - a) * (p - b) * (p - c));
printf("三角形的面积:%.2f\n", s);
}
//不管输入多少,都一直显示结果为0