This code defines a simple C++ program that models a...

This code defines a simple C++ program that models a circle using a Circle class and calculates its area and circumference. Here's what the code does step by step:

1. Include Required Libraries:

   • #include <iostream>: Used for input and output operations.
   • #include <cmath>: Provides mathematical constants (like M_PI) and functions.

2. Define the Circle Class:

   • The Circle class has one private member variable, radius, which stores the radius of the circle.
   • It has a constructor Circle(double r) that initializes the radius with the given value r.

3. Define Member Functions:

   • getArea(): A public member function that calculates and returns the area of the circle using the formula: [ \text{area} = \pi \times \text{radius}^2 ]
   • getCircumference(): A public member function that calculates and returns the circumference of the circle using the formula: [ \text{circumference} = 2 \times \pi \times \text{radius} ]

4. Main Function:

   • Creates a Circle object c with a radius of 5.0.
   • Calls c.getArea() to calculate the area of the circle and prints it using std::cout.
   • Calls c.getCircumference() to calculate the circumference of the circle and prints it.

5. Input and Output:

   • The input (radius) is hardcoded as 5.0 in the example.
   • The output is the calculated area and circumference of the circle:

     Area: 78.5398
     Circumference: 31.4159
     

     (these values are based on (\pi \approx 3.14159)).

In summary, this code calculates and prints the area and circumference of a circle with a radius of 5.