public class Circle {

private double radius;

public Circle() {

this(1.0);

}//no arg ctor

public Circle(double radius) {

this.radius = radius;

}//end ctor

public double getRadius() {

return radius;

}//end getRadius

public void setRadius(double radius) {

this.radius = radius;

}//end setRadius

public double circumference() {

return 2 * Math.PI * radius;

}//end circumference

public double area() {

return Math.PI * Math.pow(radius, 2);

}//end area

}//end Circle class