HZNUOJ


Problem_ID: B
Result: Accepted
Time: 6ms
Memory: 1116kB
Author: 2018212212060
In contest: 1273

#include<stdio.h>
#include<math.h>
int main(void){
int a,b,c;
while(scanf("%d%d%d",&a,&b,&c)!=EOF){
	if(a+b>c&&a+c>b&&b+c>a){
	double p=(a+b+c)*1.0/2;
	printf("%.2f\n",sqrt(p*(p-a)*(p-b)*(p-c)));
	}
	else{
	printf("invalid triangle\n");}
}
}