View Code of Problem 24

#include<stdio.h>
#include<math.h>
void main(){
	double a,b,c,d,s;
	while(scanf("%lf %lf %lf",&a,&b,&c)!=EOF){
	
  
  	if(a+b>c&&a+c>b&&b+c>a)
        {
        	d=(a+b+c)/2;
          	s=sqrt(d*(d-a)*(d-b)*(d-c));
            printf("%lf",s);
        
        }
	else{
	
	printf("不能构成三角形");	
	}
}
}