#include<iostream.h>
class HCN
{
private:
float d,r;
public:
HCN (float d,float r)
{
this->d=d;
this->r=r;
}
float tinhchuvi();
friend float tinhdientich(HCN h);
void inthongtin();
friend void nhap(HCN &h);
};
void HCN :: inthongtin()
{
cout<<"("<<d<<","<<r<<")";
}
float HCN :: tinhchuvi()
{
return 2*(d+r);
}
float tinhdientich(HCN h)
{
return h.d*h.r ;
}
void nhap(HCN &h)
{
cout<<"\nmoi nhap chieu dai";cin>>h.d;
cout<<"\nmoi nhap chieu rong";cin>>h.r;
}
int main()
{
HCN h(20,15);
//h.nhap();
nhap(h);
cout<<"\nIn thong tin hinh chu nhat: ";
h.inthongtin();
cout<<"\n co chu vi la: "<<h.tinhchuvi()<<"\n va co dien tich la: "<<tinhdientich(h);
cout<<endl;
return 0;
}