Test. .

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

int main()
{
int subme;
char menu;
atas:
clrscr();
cout<<"_____________________________________________"<<endl;
   cout<<"\t\tProgram luas bangun ruang"<<endl;
   cout<<"_____________________________________________"<<endl;
cout<<"Pilih Menu Program \n";
cout<<"\n1. Luas Lingkaran\n";
cout<<"2. Luas Bujursangkar\n";
cout<<"3. Luas Segitiga\n";
cout<<"4. Luas Trapesium\n";
cout<<"5. Luas Layang-layang";
cout<<"\nPilih program yang akan dijalankan : ";
cin>>subme;

switch (subme)
{
case 1:
{
float r,L;
   cout<<"_______________________________\n";
cout<<"\nInput jari-jari : ";
cin>>r;
L=3.14*r*r;
cout<<"Luas Lingkaran  = "<<L<<endl;
} break;

case 2:
{
float s,L;
   cout<<"_______________________________\n";
cout<<"\nInput sisi  : ";
cin>>s;
L=s*s;
cout<<"Luas Bujursangkar = "<<L<<endl;
} break;

case 3:
{
float a,t,L;
   cout<<"_______________________________\n";
cout<<"\nInput alas    : ";
cin>>a;
cout<<"Input tinggi  : ";
cin>>t;
L=a*t/2;
cout<<"Luas Segitiga : "<<L<<endl;
} break;

case 4:
{
float s1,s2,t,L;
   cout<<"_______________________________\n";
cout<<"\nInput sisi ke-1 : ";
cin>>s1;
cout<<"Input sisi ke-2 : ";
cin>>s2;
cout<<"Input tinggi    : ";
cin>>t;
L=s1*s2*t/2;
cout<<"Luas Trapesium  : "<<L<<endl;
} break;

case 5:
{
float d1,d2,L;
   cout<<"_______________________________\n";
cout<<"\nInput diagonal ke-1 : ";
cin>>d1;
cout<<"Input diagonal ke-2 : ";
cin>>d2;
L=d1*d2/2;
cout<<"Luas Layang-layang  : "<<L<<endl;
} break;
}
cout<<"\n\nApakah akan mengulang kembali <y/n> ?";
   cin>>menu;
   if (menu == 'y'||menu=='Y')
{
goto atas;
}
else
{
cout<<"\nTerima Kasih sudah menggunakan program ini";
}
getch ();}