javalab12.java

import java.util.Scanner;

abstract class Shape{
    abstract double rectanglearea(double num1, double num2);
    abstract double squarearea(double num3);
    abstract double circlearea(double num4);
}

class shapedemo extends Shape{
    double rectanglearea(double num1,double num2)
    {
        return num1*num2;
    }
    double squarearea(double num3)
    {
        return num3*num3;
    }
    double circlearea(double num4)
    {
        return (3.14)*num4*num4;
    }
}

public class javalab12 {
    public static void main(String[] st)
    {
        Scanner sc = new Scanner(System.in);
        Shape ob;
        shapedemo obj = new shapedemo();
        ob = obj;
        
        System.out.print("Enter side 1 of rectangle:");
        double n1 = sc.nextDouble();
        System.out.print("Enter side 2 of rectangle:");
        double n2 = sc.nextDouble();
        System.out.println("Area of rectangle: " + ob.rectanglearea(n1,n2));

        System.out.print("Enter side of square:");
        double n3 = sc.nextDouble();
        System.out.println("Area of Square: " + ob.squarearea(n3));

        System.out.print("Enter radius of circle:");
        double n4 = sc.nextDouble();
        System.out.println("Area of cirle: " + ob.circlearea(n4));
    }
}