Define a class name ComparableCircle that extends Circle and implements Comparable interface. Draw the UML diagram and implement the compareTo() method to compare the circles on the basis of area. Write a test class to find the larger of two instances of ComparableCircle objects. class Circle {protected double radius;// Default constructorpublic Circle() {this(1.0);}// Construct circle with specified radiuspublic Circle(double radius) {this.radius = radius;}// Getter method for radiuspublic double getRadius() {return radius;}// Setter method for radiuspublic void setRadius(double radius) {this.radius = radius;}// Implement the findArea method defined in GeometricObjectpublic double findArea() {return radius*radius*Math.PI;}// Implement the findPerimeter method defined in Geometricobjectpublic double findPerimeter() {return 2*radius*Math.PI;}// Override the equals() method defined in the Object classpublic boolean equals(Circle1 circle) {return this.radius == circle.getRadius ();}// Override the tostring() method defined in the Object classpublic String toString() {return "[Circle] radius = " + radius;}}

The given problem is realated to java programming and desiging UML class diagram where the new class ComparableCircle will be created having relationship with existing Circle class.The new class ComparableCircle will extend Circle and implement comparable interface It will have a method to compare the circles that takes a parameter of Circle object. If current object's area is same as passed object's area, then it will return 0, otherwise will return 1. Area will be retrieved by calling the method: findArea()ComparableCircle will extend Circle. ComparableCircle will implement Comparable The diagram is as below: public class ComparableCircle extends Circle implements Comparable<Circle>{ ComparableCircle(){ } ComparableCircle(double radius){ super(radius);//calls Circle(double) } @Override public int compareTo(Circle other) { if(super.findArea()==other.findArea())//if his call's object-> findArea is same as passed's findArea return 0;//return 1 else if(super.findArea()>other.findArea()){ return 1;//if this object is larger, return 1 }//end if-else else { return -1;//if other object is larger } }//end compareTo }//end classpackage junitTestCase; public class Driver { public static void main(String[] args) { //create 2 objects of ComparableCircle ComparableCircle circle1 = new ComparableCircle(10); ComparableCircle circle2 = new ComparableCircle(12); if(circle1.compareTo(circle2)==-1) {//if compareTo returns 0, then test case is passed as both are same System.out.println("Pass"); } else {//if returned 0 System.out.println("Fail"); } }}In main driver class, the output will be as below: