C + + program to calculate the area of ​​a circle, square area, circumference of a circle

Calculate the area of ​​a circle, square or circle around the area may need branching to the program, and for now I use a switch case.
Directly to the heart of the matter, I've created this program as simple as possible to avoid mistakes for new programmers to learn,,
This time I give direct his script c + +, so you can simply copy and paste :



#include <iostream.h>
#include <conio.h>
#include <iomanip.h>

main() {
     int l,p,r,pil,t;
     float Luas,Kel;
     const float phi=3.14;
     bool jwb;

cek:
cout<<"Pilihan menu :\n";
cout<<"[1] Luas Lingkaran \n";
cout<<"[2] Luas Persegi \n";
cout<<"[3] Keliling Lingkaran \n";
cout<<"Masukkan pilihan anda : ";cin>>pil;

switch (pil){
    case 1 :
       cout<<"Masukkan jari-jari : ";cin>>r;
      Luas=phi*(r*r);
      cout<<"\nLuas Lingkaran : "<<Luas<<endl<<endl;
      cout<<"Anda ingin mengulang?[1=ya,0=tdk] ";cin>>jwb;
      if(jwb==1)
        goto cek;
      else
        cout<<"Terima kasih";
      break;
   case 2 :
       cout<<"Masukkan panjang : ";cin>>p;
      cout<<"Masukkan lebar : ";cin>>l;
      Luas=p*l;
      cout<<"\nLuas Persegi : "<<Luas<<endl<<endl;
      cout<<"Anda ingin mengulang?[1=ya,0=tdk] ";cin>>jwb;
      if(jwb==1)
        goto cek;
      else
        cout<<"Terima kasih";
      break;
   case 3 :
       cout<<"Masukkan jari-jari : ";cin>>r;
      Kel=(phi*r)*2;
      cout<<"\nKeliling Lingkaran : "<<Kel<<endl<<endl;
      cout<<"Anda ingin mengulang?[1=ya,0=tdk] ";cin>>jwb;
      if(jwb==1)
        goto cek;
      else
        cout<<"Terima kasih";
      break;
   default :
       cout<<"Maaf pilihan menu yang anda inputkan tidak terdaftar ";}

getch();}


And when you run the program, the display will come out like this: 

You now can select the menu :)