/*Create
a C++ base class Shape. Derive three different classes Circle, Sphere and
Cylinder from shape class. Write a C++ program to calculate area of Circle,
Sphere(4 π r2) and Cylinder(2πr (h + r) ). (Use pure virtual function). */
#include<conio.h>
#include<stdlib.h>
class
shape
{
public:
virtual
void area()=0;
};
class
circle:public shape
{
public:
int
r;
void
getc()
{
cout<<"\nenter
the radius:";
cin>>r;
}
void
area();
};
class
Sphere:public shape
{
public:
int
r1;
void
getr()
{
cout<<"\n
Enter the radius:";
cin>>r1;
}
void
area();
};
{
public:
int
r2,h;
void
gett()
{
cout<<"\n
Enter the radius2 & height:";
cin>>r2>>h;
}
void
area();
};
void
circle::area()
{
cout<<(3.14*r*r);
}
void
Sphere::area()
{
cout<<(4*3.14*r1*r1);
}
void
Cylinder::area()
{
int
d=h+r2;
cout<<
d;
cout<<(2*3.14*r2*d);
}
void
main()
{
clrscr();
int
ch;
circle
c;
Sphere
S;
Cylinder
t;
do
{
cout<<"\n1.Area
of circle";
cout<<"\n2.Area
of Sphere";
cout<<"\n3.Area
of cylinder";
cout<<"\n4.Exit";
cout<<"\nEnter
your choice:\t";
cin>>ch;
switch(ch)
{
case
1:
c.getc();
cout<<"Area
of circle:";
c.area();
break;
case
2:
S.getr();
cout<<"Area
of Sphere:";
S.area();
break;
case
3:
t.gett();
cout<<"Area
of cylinder:";
t.area();
break;
case
4:
exit(0);
}
}while(ch!=4);
getch();
};
