#include <iostream>
using namespace std;

class Shape
{
public:
    virtual void area() = 0;
    virtual void name()
    {
        cout << "This is a shape" << endl;
    }
    virtual ~Shape() {}
};

class Circle : public Shape
{
    float r;

public:
    Circle(float x)
    {
        r = x;
    }
    void name()
    {
        cout << "This is a circle" << endl;
    }
    void area()
    {
        cout << "Area = " << 3.14 * r * r << endl;
    }
};

class Rectangle : public Shape
{
    float l, b;

public:
    Rectangle(float x, float y)
    {
        l = x;
        b = y;
    }
    void name()
    {
        cout << "This is a rectangle" << endl;
    }
    void area()
    {
        cout << "Area = " << l * b << endl;
    }
};

class Triangle : public Shape
{
    float b, h;

public:
    Triangle(float x, float y)
    {
        b = x;
        h = y;
    }
    void area()
    {
        cout << "Area = " << 0.5 * b * h << endl;
    }
};

int main()
{
    float r, l, b, tb, h;
    cout << "Enter radius of circle: ";
    cin >> r;
    cout << "Enter length and breadth of rectangle: ";
    cin >> l >> b;
    cout << "Enter base and height of triangle: ";
    cin >> tb >> h;

    Shape *s[3];
    s[0] = new Circle(r);
    s[1] = new Rectangle(l, b);
    s[2] = new Triangle(tb, h);

    cout << endl;
    for (int i = 0; i < 3; i++)
    {
        s[i]->name();
        s[i]->area();
        cout << endl;
    }

    for (int i = 0; i < 3; i++)
        delete s[i];

    return 0;
}