Area of Circle square triangle using circle using runtime polumorphism

[HS05669]

[/code]

[coder777]

You never call show_info() which is a bit weird name for getting input...

[keskiverto]

And you have no virtual functions. Polymorphism is very much about all Shapes being Shapes, but some Shapes behaving a bit more roundish way.

Consider this:

void test( const Shape& s ) {
  s.display();
}

int main()
{   
  // create object x

 test( x );
}

The x could be Triangle or Square or Circle, but the test() should not need to know that.
Alas, your class Shape does not have member display() const.

[seeplus]

The issue with having Shape() obtain 2 values is that for square and circle you only need one value. Perhaps a simple way without using polymorphism is:

#define _USE_MATH_DEFINES
#include <iostream>
#include <cmath>
#include <string>
using namespace std;

class Shape {
public:
	double a {}, b {};

	Shape(const string& txt, bool ask2 = false) {
		cout << txt;
		getData(ask2);
	}

protected:
	void getData(bool ask2 = false) {
		if (ask2) {
			cout << "Enter 2 values: ";
			cin >> a >> b;
		} else {
			cout << "Enter value: ";
			cin >> a;
		}
	}
};

class Triangle : public Shape {
public:
	Triangle() : Shape("For triangle, ", true) {}

	void display() const {
		cout << "Area of triangle " << 0.5 * a * b << '\n';
	}
};

class Square : public Shape {
public:
	Square() : Shape("For square, ") {}

	void display() const {
		cout << "Area of Square " << a * a << '\n';
	}
};

class Circle : public Shape {
public:
	Circle() : Shape("For circle, ") {}

	void display() const {
		cout << "Area of Circle " << M_PI * a * a << '\n';
	}
};

int main()
{
	Triangle t;
	t.display();

	Square s;
	s.display();

	Circle c;
	c.display();
}

For triangle, Enter 2 values: 4 5
Area of triangle 10
For square, Enter value: 5
Area of Square 25
For circle, Enter value: 3
Area of Circle 28.2743

[seeplus]

The OP has removed the original post. Ahhhhhhh...