javalab13.java

import java.util.Scanner;

interface interdemo{
    void volume();
}

class cone implements interdemo{

    double r,h;
    cone(double r,double h)
    {
        this.r = r;
        this.h = h; 
    }
    public void volume(){
        System.out.println("volume of cone: " + 0.33*3.14*r*h);
    }
}

class cylinder implements interdemo{

    double r;
    cylinder(double r)
    {
        this.r = r;
    }
    public void volume(){
        System.out.println("volume of cone: " + 0.66*3.14*r*r*r);
    }
}

class hemisphere implements interdemo{
    double r, h;
    hemisphere(double r, double h)
    {
        this.r = r;
        this.h = h;
    }
    public void volume(){
        System.out.println("volume of cone: " + 3.14*r*2*h);
    }
}

public class javalab13 {
    public static void main(String[] st)
    {
        Scanner sc = new Scanner(System.in);
        interdemo ob;
        
        System.out.print("Enter height of cone:");
        double n1 = sc.nextDouble();
        System.out.print("Enter radius of cone:");
        double n2 = sc.nextDouble();
        cone obj1 = new cone(n2,n1);
        ob = obj1;
        ob.volume();

        System.out.print("Enter radius of cylinder:");
        double n3 = sc.nextDouble();
        cylinder obj2 = new cylinder(n3);
        ob = obj2;
        ob.volume();

        System.out.print("Enter height of hemisphere:");
        double n4 = sc.nextDouble();
        System.out.print("Enter radius of hemisphere:");
        double n5 = sc.nextDouble();
        hemisphere obj3 = new hemisphere(n5,n4);
        ob = obj3;
        ob.volume();
    }
}