C++ TUTORIAL FOR BEGINNERS: Program to calculate Circumference, Area of a Circle, and the Volume of a Sphere

The Basketball ball of the NBA has a standard dimension of 4.7 inch in radius, 9.4 inch in diameter, 29.5 inches in circumference,  22 ounces (size 7) in weight, and 7.5 - 8.5 pounds per square inch of air pressure.

Objective: Calculation of the Circumference, Area of a Circle and the Volume of a Sphere
Directive: #include <iostream>, #include <cmath>
Namespace: std
Function: main
Variables:
CircleRadius
double CircleCircumference
double CircleArea
double SphereVolume
Data types of variables: double
Statements: cout, cin, return
Input: Radius of the circle
Output:
Circumference of the Circle
Area of the Circle
Volume of the Sphere

C++ source code:

/*
PROGRAM : Circumference, Area of a Circle; Volume of a Sphere
AUTHOR: eternaltreasures
DATE: 2010 September 1
*/

#include <iostream>
#include <cmath>
using namespace std;

#define PI 3.14159
#define NEWLINE '\n'     

int main ()
{

double CircleRadius;
double CircleCircumference;
double CircleArea;
double SphereVolume;


cout << "Enter the Radius of the Circle = ";
cin >> CircleRadius;

// Circumference of a Circle
CircleCircumference = 2 * PI * CircleRadius;
cout << "Circumference of the Circle = " << CircleCircumference;
cout << NEWLINE;

// Area of a Circle
CircleArea = PI * pow(CircleRadius, 2);
cout << "Area of the Circle = " << CircleArea;
cout << NEWLINE;

// Volume of a Sphere
SphereVolume = 4 * PI/3 * pow(CircleRadius, 3);
cout << "Volume of the Sphere = " << SphereVolume;
cout << NEWLINE;

return 0;
}