Answer to Question #131248 in C++ for MD RASEL BHUYAN

Question

(Single Inheritance) Write a program to create a class CIRCLE with one field as radius, used

to calculate the area of a Circle. Create another class RECTANGLE used to calculate the area

of the rectangle which is a subclass of CIRCLE class. Use the concept of single inheritance

such that the radius of circle class can be re-used as length in rectangle class. Take necessary

data members and member functions for both the classes to solve this problem. All the data

members are initialized through the constructors. Show the result by accessing the area

method of both the classes through the objects of rectangle class

Answer 1

#include <iostream>

using namespace std;

class Circle
{
protected:
    double radius{};

public:
    void setRadius(double radius)
    {
        this->radius = radius;
    }

    virtual double getArea()
    {
        return 3.14 * radius * radius;
    }
};

class Rectangle : public Circle
{
public:
    double getArea() override
    {
        return radius * radius;
    }

};

int main()
{

    Rectangle r;
    r.setRadius(20);
    cout <<"Area of Rectangle: "<< r.getArea() <<endl;
    cout <<"Area of Circle: "<< r.Circle::getArea() ;

    return 0;
}