Speedometer in applet

import java.applet.*;
import java.awt.*;
import java.lang.*;
import java.math.*;
import java.awt.Color;


/*<applet code="speed" height=678 width=678></applet>
  */
public class speed extends Applet implements Runnable

{
int i=0,j=180,p=1;
double x,y;
String un="";

Thread t;
public void init()
{
t=new Thread(this);
t.start();
}
public void run()
{

try
{
while(true)
{
repaint();
t.sleep(100);

}
}catch(Exception e)
{
System.out.println(e);
}
}

public void update(Graphics g)
{
paint(g);
}

public void paint(Graphics g)
{
g.setColor(Color.yellow);
g.fillOval(100,100,536,536);
g.setColor(Color.blue);
g.fillOval(138,138,460,460);
g.setColor(Color.yellow);

x=368+ 230*Math.cos(Math.toRadians(j));
y=368+ 230*Math.sin(Math.toRadians(j));
g.drawLine((int)x,(int)y,368,368);
g.setColor(Color.black);

for(int pr=0;pr<=270;pr++)
{

if(pr%10==0)
{

un="";
un=un+pr;

g.drawString(un,(int)(368+ 230*Math.cos(Math.toRadians(pr-180))),(int)(368+ 230*Math.sin(Math.toRadians(pr-180))));
}
}

g.drawLine((int)x,(int)y,368,368);
// y=sqrt(r^2-(x-h)^2)+k

g.setColor(Color.black);


if(i==0)
{
j=j+10;

if(j==450)
{
i=1;

}
}
else
{
j=j-10;

if(j<=180)
{
i=0;

}

}

}
}