#include#includevoid main(){float a,b,c,s,p;printf("please input the a,b,c:");scanf("%f%f%f",&a,&b,&c);p=(a+b+c)/2;s=sqrt(p*(p-a)*(p-b)*(p-c));printf("when a=%f\tb=%f\tc=%f\t\ns%f=",a,b,c,s);}