using System;

public class circle {   

    protected double radius;

    public circle (double circleRadius) {

        setRadius(circleRadius);

    }

    public void setRadius(double circleRadius){

        radius = circleRadius;

    }

    public double getRadius(){

        return radius;

    }

    public double calaArea(){

        return Math.Pi* radius * radius;

    }

    public double calcVolume(){

        return 0;

    }

}

​

public class Cylinder_extends_circle {

    protected double height;

    public Cylinder(double cylHeight, double circleRadius){

        super(circleRadius);

        setHeight(cylHeight);

    }

    public void setHeight(double cylHeight){

        height = cylHeight;

    }

    public double getHeight() {

        return height;

    }

    public double calcVolume(){

        return super.calcArea() * height;

    }

}