import javax.swing.*;
import java.awt.*;
import static java.lang.Math.*;

/*
<applet code="N_gon.class" width="220" height="220"> 
<param name="NumPoints" value="8">
</applet>
*/

public class N_gon extends JApplet {
  int numPoints;
  int sc = 100;

  @Override     
  public void init() {
    // Integer.parseInt --- Stringから intへの変換
    numPoints = Integer.parseInt(getParameter("NumPoints"));
  }

 @Override  
  public void paint(Graphics g) {
    int i;
    double theta1, theta2;
    for(i=0; i<numPoints; i++) {
      // 単位 ラジアン
      theta1 = PI*2*i/numPoints;      // 360*i/n度
      theta2 = PI*2*(i+1)/numPoints;  // 360*(i+1)/n度
      g.drawLine((int)(sc*(1.1+cos(theta1))), 
   		 (int)(sc*(1.1+sin(theta1))),
                 (int)(sc*(1.1+cos(theta2))),
   		 (int)(sc*(1.1+sin(theta2))));
    }
  }
}