Program menghitung Volume bola

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

class volume_bola {
public:
void volume();
void hitung();
private:
float v,r;
};
void volume_bola::volume(){
cout<<"PROGRAM MENGHITUNG VOLUME bola"<<endl;
cout<<"nilai r : "; cin>>r;
}
void volume_bola::hitung(){
v=4/3*(3.14*r*r*r);
cout<<"Volume Bola = " << v;
cout<<endl;
}
int main(){
volume_bola x;
x.volume();
x.hitung();

getch();
return 0;
}