Question

Please write in Java Language

Write an abstract class Shape with an attribute for the name of the shape (you'll use this later to identify a particular shape). Include a constructor to set the name of the shape and an abstract calculateArea method that has no parameters and returns the area of the shape. Optionally, include a constructor that returns the name of the shape and its area (by calling the calculateArea method).

Write a Rectangle class that inherits from Shape with attributes for the length and width of the rectangle. Include a constructor to set the length and width attributes (don't forget about the Shape constructor!). Be sure to override the calculateArea method!

Write a Circle class that inherits from Shape with an attribute for the radius of the circle. Include a constructor to set the radius attribute. (don't forget about the Shape constructor!). Be sure to override the calculateArea method. To use pi, simply type Math.PI.

Test it out in a driver! Make a circle and a rectangle and print out the objects (if you wrote the toString method, otherwise, just print out the area of the circle and the rectangle).

Answer 1

abstract class Shape {
   private String name;

   public Shape(String aName) {
       super();
       name = aName;
   }

   public String getName() {
       return name;
   }

   public void setName(String aName) {
       name = aName;
   }

   public abstract double calculateArea();
}

class Rectangle extends Shape {

   private int width;
   private int length;

   public Rectangle(String aName, int aWidth, int aLength) {
       super(aName);
       width = aWidth;
       length = aLength;
   }

   @Override
   public double calculateArea() {
       return width * length;
   }

}

class Circle extends Shape {
   private double radius;

   public Circle(String aName, double aRadius) {
       super(aName);
       radius = aRadius;
   }

   public double getRadius() {
       return radius;
   }

   public void setRadius(double aRadius) {
       radius = aRadius;
   }

   @Override
   public double calculateArea() {
       double a = Math.PI * radius * radius;
       return a;
   }
}

public class TestShape {
   public static void main(String[] args) {
       Shape r = new Rectangle("Rectangle : ", 10, 15);
       System.out.println("Area : " + r.calculateArea());
       r = new Circle("Circle", 5);
       System.out.println("Area : " + r.calculateArea());

   }
}