Answer:
The following program written in c++:
#include <iostream>
using namespace std;
class Circle //define class
{
private : //access modifier
double pi, radius, area; // set double type variables
public :
Circle (double radius = 0.0) //define constructor
{
pi = 3.1415;
this->radius = radius;
}
void setRadius (double radius) // define void type method
{
if (radius < 0){ // if the radius is negative don't take it
cout << "Radius can't be negative." << endl;
return;
}
this->radius = radius;
}
double getArea () // define double type method
{
area = pi * radius * radius;
return area;
}
};
class Rectangle //define class
{
private: //access modifier
double length ,breadth ,area; // set double type private data types
public:
Rectangle (double length = 0.0, double breadth = 0.0) // define constructor
{
this->length = length;
this->breadth = breadth;
}
void setDimension (double length , double breadth ) // define void type method
{
if (length < 0 || breadth < 0){ //set if condition, if the dimensions is negative than don't take it
cout << "Dimensions can't be negative." << endl;
return;
}
this->length = length;
this->breadth = breadth;
}
double getArea () // define double type method
{
area = length * breadth;
return area;
}
};
int main() //main function
{
int choice; //integer type variable
double radius, length, breadth;
Circle c;
Rectangle r;
cout << "Select ( 1 ) Circle or select ( 2 ) Rectangle : "; // get the choice of user
cin >> choice;
switch (choice)
{
case 1 : cout << "Enter radius of circle : ";
cin >> radius;
c.setRadius(radius);
cout << "Area of circle is : " << c.getArea();
break;
case 2 : cout << "Enter dimensions of rectangle : ";
cin >> length >> breadth;
r.setDimension(length,breadth);
cout << "Area of rectangle is : " << r.getArea();
break;
default : cout << "Invalid Selection...";
}
return 0;
}
Explanation:
Here, we define two classes "Circle" and "Rectangle"
Then, we create first two function which get the value from the user.
Then, we create the second two functions which return the calculation of the following formulas.
