#include <iostream>
#include <cmath>
#include <iomanip>
using namespace std;
int main() {
int a,b;
cin>>a>>b;
double r=0.5*a*b;
double h=sqrt(a*a+b*b);
cout <<fixed<< setprecision(2);
cout <<r<<endl;
cout <<h<<endl;
return 0;
}

coi thử đr k ạ,sai thì nói nha

#include <iostream>
#include <cmath>
#include <iomanip>
using namespace std;
int main() {
int x,y;
cin>>x>>y;
double r=0.5*x*y;
double h=sqrt(x*x+y*y);
cout <<fixed<< setprecision(2);
cout <<r<<endl;
cout <<h<<endl;
return 0;
}