SOURCE

#include <stdio.h>
#include <math.h>
int main() {
    double a, b, c, p, ans;
    printf("请输入三角形的三个边: ");
    scanf("%lf %lf %lf", &a, &b, &c);
    if (a + b > c && a + c > b && b + c > a) {
         p = (a + b + c) / 2.0;
         ans = sqrt(p * (p - a) * (p - b) * (p - c));
        printf("三角形的面积为: %lf\n", ans);
    } else {
        printf("这三条边无法构成三角形\n");
}  return 0；
}