#include <iostream>
#include <cmath>
using namespace std;
int main()
{
int a, b, c, p, S;
cout<<"Введите сторону a ";
cin>>a;
cout<<"Введите сторону b ";
cin>>b;
cout<<"Введите сторону c ";
cin>>c;
p=(a+b+c)/2;
cout<<p;
S=sqrt((p*(p-a)*(p-b)*(p-c)));
cout<<"S=";
return 0;
}
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