A Simple Circle, or is it?

Question

I'm trying to make a simple program that will take the input integer, radius, and apply it to the area formula a=(3.14)r^2. for some reason i can't get the math right in the language.
Here is my code.
import javax.swing.JOptionPane;
public class Circle{
public static void main(String args [])
     String radius;
     int r, a;
     radius = JOptionPane.showInputDialog("Enter the circle radius:");
     r = Integer.parseInt(radius);
     a = Math.PI * r;//how do i get this line to work, and change r to r^2?
JOptionPane.showMessageDialog(null,     "Area is " + a);
     System.exit(0);
Any hints or help you can offer is awesome. Thanks in advance!

Answer 1

Also a is an int and PI is a double so you will need to change a into a double or cast the result to int (this truncates the decimals).
double a;
a = Math.PI * r * r;or
a = (int) (Math.PI * r * r);