Volume of a Cylinder

// Created by Tan
// Program designed to output volume of a cylinder.
// User is asked for value of Radius and Height, then Volume is output.
// Formula used: V= pi*r^2*h
// Pi = 3.14159265

#include <iostream> // Needed for Cin Cout

using namespace std;

int main()
{
    double d_Volume, d_Pi, d_Radius, d_Height; // Names of variables in our equations. Added a prefix of " d_ " to improve syntax highlighting.
    cout << "+++++++++++++++++++++++++++++++++++++++" << endl;
    cout << "Cylinder Volume Calculator by Tan" << endl;
    cout << "Input the radius and height of the cylinder whose volume you'd like calculated." << endl;
    cout << "Formula used: Volume = Pi*Radius^2*Height" << endl;
    cout << "Value of Pi is to 9 figures." << endl;
    cout << "+++++++++++++++++++++++++++++++++++++++" << endl;

    cout << "What is the radius of your cylinder?" << endl;
    cin >> d_Radius; // Radius is stored as a number

    cout << "What is the height of your cylinder?" << endl;
    cin >> d_Height; // Height is stored as a number

    d_Pi = 3.14159265;

    d_Volume = d_Pi*pow(d_Radius, 2) * d_Height;

    cout << "The volume of your cylinder is: " << d_Volume << endl;

    system("pause");
    return 0;
}

// Variables