Area And Perimeter Of Triangle - Decimal Formatting Error?

I am also having trouble with another program.

Java Code:

import javax.swing.JOptionPane;
import java.util.*;
import java.text.DecimalFormat;
import java.util.StringTokenizer;
public class ShelbyHarms_3_03 {
public static void main (String [] args) {
double a, b, c; //Input sides of triangle
double x; //Perimeter of triangle
double area; //Area of triangle

[Code] .....

Here are the errors:

ShelbyHarms_3_03.java:39: error: variable x might not have been initialized
JOptionPane.showMessageDialog(null, formatter.format(x));
^
ShelbyHarms_3_03.java:42: error: variable area might not have been initialized
JOptionPane.showMessageDialog(null, formatter.format(area));
^
2 errors

Am I not formatting the decimal format right?