java/w4/Circle.java

package w4;

public class Circle extends Shape {
    private double radius; 
    public Circle() {}

    public Circle(double radius) {
        this.radius = radius;
    }

    @Override
    public double getArea() {
        return Math.PI * radius * radius;
    }

    public double getRadius() {
        return radius;
    }

    public void setRadius(double radius) {
        this.radius = radius;
    }
}