Sorting ArrayList Of Geometric Objects By Area From Smallest To Largest

I have to create a method with the following header :

public static <E extends Comparable<E> > void sort ( ArrayList<E> list , int left, int right)

i also had to create a swap cells method and position of max integer method. and also had to read the preserved data file in with a scanner. I implemented the comparable interface I am having difficulty sorting my list by the area. It has to be in descending order.

Geometric Object class: since it has comparator also am interested if i need to change this?

CODE:

Driver:
public static void main(String[] args) throws IOException, ClassNotFoundException {
Circle c1 = new Circle (4, "red", false);
Circle c2 = new Circle (2, "blue", true);
Circle c3 = new Circle (10, "blue", true);
Rectangle r1 = new Rectangle (10, 6, "yellow", true);
Rectangle r2 = new Rectangle ( 5, 11, "green", true);
ArrayList <GeometricObject> list = new ArrayList();

[Code] ....