/*

	........name, date, instructor, blah blah blah............
	Multi-line comments
	...........
	Compiling g++ loop1.cpp -o loop1.out
	Execution..................
	
	Goal: : The program will calculate the area of a circle.


*/


#include <iostream>	//cin, cout, fixed, showpoint, endl
#include <iomanip>	// for setprecision


using namespace std;

int main()
{
	// 1. variable declaration
	const float PI= 3.14;
	cout << fixed << showpoint << setprecision(1);

	float radius, area;

	// 2. input
	cout << "Input the radius (-1 to quit): ";
	cin >> radius;

	while ( radius > 0) 	//quit the loop for negative radius
	{

		// 3. computing
		area = PI * radius * radius;
	
		//4. output
		cout << "The area is: " << area << endl;
		
		cout << "Input the radius (-1 to quit): ";
		cin >> radius;
	}
	
	
	return 0;
}