how to use super constructor in java
public class Rectangle
{
   private double length;  // To hold length of rectangle
   private double width;  // To hold width of rectangle
}
public class Box extends Rectangle
{
   private double height;
public Box(double length, double width, double height)
    {
      // Call the superclass constructor to
      // initialize length and width.
      super(length, width);
      
      // Initialize height.
      this.height = height;
   }
 }
 
public class BoxDemo
{
   public static void main(String[] args)
   {
     
     // Create a box object.
      Box myBox2 = new Box(12.2, 3.5, 2.0);
   }
}
