lab_Task.java

abstract class Shape {
    abstract double area();
    void display() {
        System.out.println("This is a shape");
    }
}

class Circle extends Shape {
    double radius;
    Circle(double radius) {
        this.radius = radius;
    }
    double area() {
        return Math.PI * radius * radius;
    }
}
class Rectangle extends Shape {
    double length, width;
    Rectangle(double length, double width) {
        this.length = length;
        this.width = width;
    }
    double area() {
        return length * width;
    }
}
public class lab_Task{
    public static void main(String[] args) {
        Shape s1 = new Circle(5);        
        Shape s2 = new Rectangle(4, 6); 
        s1.display();
        System.out.println("Circle Area: " + s1.area());
        s2.display();
        System.out.println("Rectangle Area: " + s2.area());
    }
}