Program C++ menghitung volume tabung dan luas tabung

1. #include <iostream>
#include <stdlib.h>
usingnamespace std;
intmain()
{
floatphi=3.14,r,t,v,L;
cout<<"========================================"<<endl;
cout<<"MENGHITUNG VOLUME TABUNG DAN LUAS TABUNG"<<endl;
cout<<"========================================"<<endl;
cout<<endl;
cout<<endl;
cout<<"masukkanjari-jari :";
cin>>r ;
cout<<"masukkantinggi :";
cin>>t ;
cout<<endl;
v=phi*r*r*t ;
L=2*phi*r*t ;
system("cls");
cout<<"========================================"<<endl;
cout<<"MENGHITUNG VOLUME TABUNG DAN LUAS TABUNG"<<endl;
cout<<"========================================"<<endl<<endl;
cout<<"========";
cout<<endl<<"Hasilnya"<<endl;
cout<<"========"<<endl<<endl;

2. cout<<"volume tabung:"<<v <<endl;
cout<<"luastabung : " <<L<<endl;
return0;
}