//Andres Guzman CSC5 Chapter 4, P. 225, #21
//
/**************************************************************
*
* SELECT CALCULATION OPTION
* ____________________________________________________________
* This program will allow the user to select an option to calculate.
*
* Computation is based on the formula:
* area1 = pi * pow(radius,2)
* area2 = length * width
* area3 = length * height
* ____________________________________________________________
* INPUT
* radius = Input the radius for an object
* length = Input the desired length of an object
* width = Input desired width of an object
* height = Input desired height for an object
* OUTPUT
* area1 = The area of a circle
* area2 = The area of a rectangle
* area3 = The area of a triangle
*
**************************************************************/
#include <iostream>
#include <cmath>
using namespace std;
 
int main()
{
//
//Initlaizing Variabales
	int choice;		//Holds the input for the choices
	double area1, area2, area3;		//Holds room for different areas of calculation
	double pi = 3.14159;		//Holds a fraction of pi
	double radius, length, width, height;	//Holds the different input measurements
	const int CIR_AREA = 1;		//Option 1 for the circle
	const int REC_AREA = 2;		//Option 2 for the rectangle
	const int TRI_AREA = 3;		//Option 3 for the triangle
	const int QUIT = 4;			//Option to end program
//
//Output Options
	cout << "\t\Geometry Calculator\n\n"
		 << "1. Calculate the Area of a Circle\n"
		 << "2. Calculate the Area of a Rectangle\n"
		 << "3. Calculate the Area of a Triangle\n"
		 << "4. Quit\n"
		 << "Enter your choice (1-4): ";
	cin >> choice;
//
//Initialize option selection
	switch(choice)
	{
		case 1 : cout << "\nWhat is the radius of the circle? ";
				 cin >> radius;
				 area1 = pi * pow(radius,2);	//Calculates area of circle
				 cout << "\nArea: " << area1;
				 break;
		case 2 : cout << "\nWhat is the length of the rectangle? ";
				 cin >> length;
				 cout << "\nWhat is the width of the rectangle? ";
				 cin >> width;
				 area2 = length * width;	//calculates the area of a rectangle
				 cout << "\nArea: " << area2;
				 break;
		case 3 : cout << "\nWhat is length of the Triangle? ";
				 cin >> length;
				 cout << "\nWhat is the height of the Triangle? ";
				 cin >> height;
				 area3 = length * height * .5;	//calculates the area of a triangle
				 cout << "\nArea: " << area3;
				 break;
		case 4 : cout << "\nTerminating Program.";
				 break;
		default : cout << "\nInvalid input. Please input 1, 2, 3, or 4.";
				 break;
	}
	return 0;
}