C语言编程,已知三角形的三边长a,b,c,计算求三角形面积的公式为:答:程序代码如下:include <stdio.h> include <math.h> int main(){ printf("输入三个边长:\n");float a,b,c;float s,area;scanf("%f%f%f",&a,&b,&c);s = (a+b+c)/2;area = sqrt(s*(s-a)*(s-b)*(s-c));if(a+b>c && b+c>a && a+c>b)printf("面积是%.2f\n"...