// content pane
getContentPane().setLayout( new BorderLayout() );
getContentPane().add( genderPanel, BorderLayout.WEST );
getContentPane().add( heightPanel, BorderLayout.EAST );
getContentPane().add( resultPanel, BorderLayout.SOUTH );

Complete User Interface

The unused sections (NORTH and CENTER) shrink to make room for the sections that hold components. Here is the complete GUI part of the program. (The actual application has been omitted).

import java.awt.* ;
import java.awt.event.*;
import javax.swing.*;
  
public class IdealWeight extends JFrame
{
  JRadioButton genderM, genderF;
  ButtonGroup  genderGroup;
  JPanel       genderPanel;
  
  JRadioButton heightA, heightB, heightC, heightD, heightE;
  ButtonGroup  heightGroup;
  JPanel       heightPanel;
  
  JTextField   resultText;
  JLabel       resultLabl;
  JPanel       resultPanel;
    
  public IdealWeight()  
  { 
    setTitle( "Your Ideal Weight" );
    setDefaultCloseOperation( EXIT_ON_CLOSE );
    
    // gender group
    genderM = new JRadioButton("Male", true );
    genderF = new JRadioButton("Female", false );
    genderGroup = new ButtonGroup();
    genderGroup.add( genderM );  genderGroup.add( genderF );
    genderPanel = new JPanel();
    genderPanel.setLayout(
        new BoxLayout( genderPanel, BoxLayout.Y_AXIS ) );
    genderPanel.add( new JLabel("Your Gender") );
    genderPanel.add( genderM );  genderPanel.add( genderF );
   
    // height group
    heightA = new JRadioButton("60 to 64 inches", true  );
    heightB = new JRadioButton("64 to 68 inches", false );
    heightC = new JRadioButton("68 to 72 inches", false );
    heightD = new JRadioButton("72 to 76 inches", false );
    heightE = new JRadioButton("76 to 80 inches", false );
  
    heightGroup = new ButtonGroup();
    heightGroup.add( heightA ); heightGroup.add( heightB );
    heightGroup.add( heightC ); heightGroup.add( heightD );
    heightGroup.add( heightE );
  
    heightPanel = new JPanel();
    heightPanel.setLayout(
        new BoxLayout( heightPanel, BoxLayout.Y_AXIS ) );
    heightPanel.add( new JLabel("Your Height") );
    heightPanel.add( heightA ); heightPanel.add( heightB );
    heightPanel.add( heightC ); heightPanel.add( heightD );
    heightPanel.add( heightE );
    
    // result panel
    resultText  = new JTextField(7);
    resultText.setEditable( false );   
    resultLabl  = new JLabel("Ideal Weight");
    resultPanel = new JPanel();
    resultPanel.add( resultLabl );
    resultPanel.add( resultText );
    
    // content pane
    getContentPane().setLayout( new BorderLayout() );
    getContentPane().add( genderPanel, BorderLayout.WEST );
    getContentPane().add( heightPanel, BorderLayout.EAST );
    getContentPane().add( resultPanel, BorderLayout.SOUTH  );
  }
  
  public static void main ( String[] args )
  {
    IdealWeight weightApp  = new IdealWeight() ;
    weightApp.setSize( 250, 225 );   
    weightApp.setVisible( true );        
  }
}