
#include<iostream>
#include<conio>
void main()
{
double r,luas, kel, phi=3.14 ;
cout<<"mecari luas dan persegi panjang\n";
cout<<"-------------------------------\n";
cout<<"masukkan jari-jari = "; cin>>r;
cout<<endl;
luas=phi*r*r;
kel=2*phi*r;
cout<<"jadi...