#include <iostream>
#include <iomanip>
#include <string>
#include <cmath>

using namespace std;

int main()
{
	double num, cir, rec, tri, pi, area, radius, length, width, base, height;
	pi = 3.14159;
	cout << "Would you like to find the area of a \n(1)Circle \n(2)Rectangle \n(3)Triangle?\n(4)Quit?\n";
	cin >> num;
	if (num == 1)
	{
		do
		{
			cout << "What is the radius of the circle?\n";
				cin >> radius;
			area = pow((pi * radius), 2);
		} while (radius <= 0);
			cout << "The area of that circle is " << area << " square units!\n";
	}
	else if (num == 2)
	{

		do
		{
			cout << "Please enter the length of the rectange:\n";
				cin >> length;
			cout << "Now please enter the width of the rectangle:\n";
				cin >> width;
			area = length * width;
		} while (length <= 0 && width <= 0);
			cout << "The area of your rectangle is " << area << " square units!\n";
	}
	else if (num == 3)
	{
		do
		{
			cout << "Please enter the base of the triangle:\n";
				cin >> base;
			cout << "Please enter the height for your triangle:\n";
				cin >> height;
			area = base * (.5 * height);
		} while (base <= 0 && height <= 0);
			cout << "The area of that triangle is " << area << " square units!\n";
	}
	else if (num == 4)
	{
		return 0;
	}

	system("pause");
	return 0;
}