In Java using the provided code

a) Define a Circle class that extends GeometricObject and contains:

1. Two double data fields named x and y that specify the centre of the circle with get methods.
2. A data field radius with a get method.
3. A no-arg constructor that creates a default circle with (0, 0) for (x, y) and 1 for radius.
4. A constructor that creates a circle with the specified x, y, and radius.
5. A method getArea() that returns the area of the circle.
6. A method getPerimeter() that returns the perimeter of the circle.

b) Define an EquilateralTriangle class that extends Triangle. The class contains:

1. One double data field named side to denote the side of the triangle. As we know, an equi- lateral triangle is a special type of triangle where the sides are of the same length.
2. A constructor that creates an EquilateralTriangle with the specified side. Pass the value of the side to Triangles constructor: Triangle(double side1, double side2, double side3). In other words, you have to call super and pass side for all three arguments: side1, side2, and side3.

c) Define a Rectangle class that extends GeometricObject. The class contains:

1. Two double data fields named side1 and side2 to denote the sides of the rectangle.
2. A no-arg constructor that creates a default rectangle with 1 for each side.
3. A constructor that creates a rectangle with the specified side1 and side2.
4. A method getArea() that returns the area of the rectangle.
5. A method getPerimeter() that returns the perimeter of the rectangle.

d) Define a Square class that extends Rectangle. The class contains:

1. One double data field named side to denote the side of the square.
2. A constructor that creates a Square with the specified side. Pass the value of the side to Rectangles constructor: Rectangle(double side1, double side2). In other words, you have to call super and pass side for both arguments: side1 and side2.
3. A method getArea() that returns the area of the square.
4. A method getPerimeter() that returns the perimeter of the square.

Coding:

public abstract class GeometricObject {

private String color = "white"; private boolean filled; private java.util.Date dateCreated; /** Construct a default geometric object */

protected GeometricObject() {

dateCreated = new java.util.Date();

}

/** Construct a geometric object with color and filled value */

protected GeometricObject(String color, boolean filled) {

dateCreated = new java.util.Date();

this.color = color; this.filled = filled;

}

/** Return color */

public String getColor() {

return color;

}

/** Set a new color */

public void setColor(String color) {

this.color = color;

}

/** Return filled. Since filled is boolean, * the get method is named isFilled */

public boolean isFilled() {

return filled;

}

/** Set a new filled */

public void setFilled(boolean filled) {

this.filled = filled;

}

/** Get dateCreated */ public java.util.Date getDateCreated() {

return dateCreated;

}

@Override

public String toString() {

return "created on " + dateCreated + " color: " + color + " and filled: " + filled;

}

/** Abstract method getArea */

public abstract double getArea();

/** Abstract method getPerimeter */

public abstract double getPerimeter();

}

class Triangle extends GeometricObject { private double side1 = 1.0, side2 = 1.0, side3 = 1.0;

/** Constructor */

public Triangle() {

}

/** Constructor */

public Triangle(double side1, double side2, double side3) {

this.side1 = side1; this.side2 = side2; this.side3 = side3;

}

/** Override method findArea in GeometricObject */

public double getArea() {

double s = (side1 + side2 + side3) / 2;

return Math.sqrt(s * (s - side1) * (s - side2) * (s - side3));

}

/** Override method findPerimeter in GeometricObject */

public double getPerimeter() {

return side1 + side2 + side3;

}

/** Override the toString method */

public String toString() {

// Implement it to return the three sides

return "Triangle: side1 = " + side1 + " side2 = " + side2 + " side3 = " + side3; }

}

class Test {

public static void main(String[] args) {

GeometricObject gObjectArray [] = new GeometricObject [4]; //Complete your code here

}

private static void printAreaAndPerimeter(GeometricObject gObject) {

//Complete your code here

}

}