#include<bits/stdc++.h> using namespace std; int main() { float x,y,z,q,s; cin>>x>>y>>z; q=(x+y+z)/2; if((x+y>z)&&(x+z>y)&&(z+y>x))

 {
 	 s=sqrt(q*(q-x)*(q-z)*(q-y));
 printf("%.2lf",s);
   } 

else
cout<<"can't'";

return 0;

}

#include #include using namespace std; int main() { double a,b,c,q,s; scanf("%lf %lf %lf",&a,&b,&c); if(a+b>c&&a+c>b&&b+c>a) { q=(a+b+c)/2; s=sqrt(q*(q-a)(q-b)(q-c)); printf("%.2f\n",s); } else printf("Can't"); return 0; }