#include <iostream>
#include <fstream>
#include <iomanip>
#include <cmath>

using namespace std;

// Data  260 degrees, 200 ft; 45o, 260'; 128o, 200'
//		 170o, 210'; 215o, 270'; 340o, 150'; 323o, 286'
// Data  309o, 186'; 111.5o, 194'; 177o, 140'; 253o, 190'; 30.5o, 164'; 324.5o, 153.9'

const double PI = 3.14159265;

int main ()
{
	double		initialAngle;
	double		initialSide;
	double		leftSide;
	double		rightSide;
	double		givenAngle;
	double		includedAngle;
	double		thirdSide;
	double		initialRadians;
	double		check;
	double		piece;
	double		area = 0.0;
	double		phi;
	double		alpha;
	ifstream	input;

	input.open("measures.txt");
	input >> initialAngle >> initialSide;
	initialRadians = initialAngle / 180 * PI;
	rightSide = initialSide;
	input >> givenAngle;
	while (givenAngle > 0)
	{
		input >> leftSide;
		check = initialAngle - 180;
		if (check < 0)
			check += 360;
		includedAngle = (check - givenAngle) / 180 * PI;
		if (includedAngle < 0)
			includedAngle += (2.0 * PI);
		piece = 0.5 * rightSide * leftSide * sin (includedAngle);
		cout << includedAngle*180/PI << "  " << piece << endl;
		thirdSide = sqrt(rightSide*rightSide + leftSide*leftSide - 
			2.0 * rightSide * leftSide * cos (includedAngle));
		cout << leftSide << "  " << rightSide << "  " << thirdSide << "  "
			<< leftSide*sin(includedAngle)/thirdSide << endl;
		area += piece;
		phi = asin (leftSide * sin (includedAngle) / thirdSide);
		alpha = asin (rightSide * sin (includedAngle) / thirdSide);
		if (fabs (phi-alpha-includedAngle) < 0.01)
			phi = PI - alpha - includedAngle;
		initialRadians = phi + initialRadians;
		if (initialRadians > 2.0 * PI)
			initialRadians -= (2.0 * PI);
		initialAngle = initialRadians * 180 / PI;
		cout << phi*180/PI << " ** " << initialAngle << endl;
		rightSide = thirdSide;
		input >> givenAngle;
	}
	cout << "The area is " << area << " square feet." << endl;
	input.close();
	return 0;
}