public class Archimedes {

    public static void main (String[] argv)
    {
	DrawTool.display ();
	DrawTool.setXYRange (-10, 10, -10, 10);
	DrawTool.drawMiddleAxes (true);

	// Radius:
	double r = 8;

	// Draw the circle.
	DrawTool.drawCircle (0,0,r);

	// Number of triangles to inscribe.
	int N = 6;

	// Interior angle of each.
	double angle = 2*Math.PI / N;

	// Initialize the variable that will accumulate the lengths
	// of edges that comprise the perimeter.
	double perimeter = 0;

	for (int i=0; i<N; i++) {

	    // One corner of the triangle on the circumference:
	    double x1 = r * Math.cos (i*angle);
	    double y1 = r * Math.sin (i*angle);

	    // The second corner:
	    double x2 = r * Math.cos ((i+1)*angle);
	    double y2 = r * Math.sin ((i+1)*angle);

	    // Distance between the two:
	    double dist = Math.sqrt ((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2));

	    // Accumulate:
	    perimeter = perimeter + dist;

	    // Draw the i-th triangle:
	    DrawTool.drawLine (0,0, x1, y1);
	    DrawTool.drawLine (0,0, x2, y2);
	    DrawTool.drawLine (x1,y1, x2, y2);
	}

	// The estimate of is the perimeter divided by the diameter:
	double piEstimate = perimeter / (2*r);
	System.out.println ("pi=" + piEstimate);
    }

}