4:write a program to implement for interfaces and method is java ?

 // Define an interface for a shape

interface Shape {

    double calculateArea();

    double calculatePerimeter();

}

// Implement the interface for a Circle

class Circle implements Shape {

    private double radius;

    public Circle(double radius) {

        this.radius = radius;

    }

    @Override

    public double calculateArea() {

        return Math.PI * radius * radius;

    }

    @Override

    public double calculatePerimeter() {

        return 2 * Math.PI * radius;

    }

}

// Implement the interface for a Rectangle

class Rectangle implements Shape {

    private double length;

    private double width;

    public Rectangle(double length, double width) {

        this.length = length;

        this.width = width;

    }

    @Override

    public double calculateArea() {

        return length * width;

    }

    @Override

    public double calculatePerimeter() {

        return 2 * (length + width);

    }

}

public class Main {

    public static void main(String[] args) {

        Circle circle = new Circle(5.0);

        System.out.println("Circle Area: " + circle.calculateArea());

        System.out.println("Circle Perimeter: " + circle.calculatePerimeter());

        Rectangle rectangle = new Rectangle(4.0, 6.0);

        System.out.println("Rectangle Area: " + rectangle.calculateArea());

        System.out.println("Rectangle Perimeter: " + rectangle.calculatePerimeter());

    }

}