Program C++ Menghitung Luas Tabung

#include<iostream>
using namespace std ;
#define phi 3.14
int main ()
{
int r,t ;
float luas ;
cout << "input jari_jari =" ;
cin >> r ;
cout << "input tinggi =" ;
cin >> t ;
luas = 2*phi*r*(r+t);
cout << "luas =" << luas;
 return 0 ;
}

Outputnya :