/** A circle. Since you can calculate the area of * circles, class implements the Measurable interface. * * Taken from Core Web Programming from * Prentice Hall and Sun Microsystems Press, * http://www.corewebprogramming.com/. * © 2001 Marty Hall and Larry Brown; * may be freely used or adapted. */ public class Circle extends Curve implements Measurable { private double radius; public Circle(int x, int y, double radius) { setX(x); setY(y); setRadius(radius); } public double getRadius() { return(radius); } public void setRadius(double radius) { this.radius = radius; } /** Required for Measurable interface. */ public double getArea() { return(Math.PI * radius * radius); } }