title: Why is my java EXTENDS not working?
body: <p>I hava a Super Class Ball with extender OvalBall. With following being my code I am getting a error message telling me I can't use the child class OvalBall. can anyone help explain please? </p>
  
  <pre><code>public class Ball                                       
  {
    private double diameter;
    private String colour;
  
    public Ball(double d, String c)
    {
      this.diameter = d;
      this.colour = c;
    }
  
    public void setDiameter(double d)
    {
      this.diameter = d;
    }
  
    public double getDiameter()
    {
      return this.diameter;
    }
  
    public void setColour(String c)
    {
      this.colour = c;
    }
  
    public String getColour()
    {
      return colour;
    }
  
    public double bounce()
    {
      double height = diameter * 2;
      return height;
    }
  
    public void roll()
    {
      System.out.println("wheeee");
    }
  
  
    public class OvalBall extends Ball
    {
      private double secondDiameter;
  
  
  
      public void setSecondDiameter(double sd)
      {
        this.secondDiameter = sd;
  
      }
  
      public double getSecondDiameter()
      {
        return this.secondDiameter;
  
      }
    }
  
  } 
  
  public class Main                                       
  {
    public static void main(String[] args)
    {
     OvalBall na = new OvalBall(4,"blue",4);
      na.setSDiameter(10);
      System.out.println(na.bounce());
    }
  }
  </code></pre>
  
  <p>Feel free to change anything.</p>
  
  <p>Thanks</p>