public class Annulus {

  private double x;
  private double y;
  private double rInner;
  private double rOuter;

  Annulus(){
    this.x = 0;
    this.y = 0;
    this.rInner = 0;
    this.rOuter = 0;
  }

// three-arg constructor gives a circle

  Annulus(double x, double y, double radius){
    this();
    this.x = x;
    this.y = y;
    this.rInner = 0;
    this.rOuter = radius;
  }

  Annulus(double x, double y, double rInner, double rOuter){
    this();
    this.x = x;
    this.y = y;
    this.rInner = rInner;
    this.rOuter = rOuter;
  }

  public double getX() { return x; }
  public void setX(double x){ this.x = x; }
  public double getY() { return y; }
  public void setY(double x){ this.y = y; }
  public double getRInner() { return rInner; }
  public void setRInner(double rInner){ this.rInner = rInner; }
  public double getROuter() { return rOuter; }
  public void setROuter(double rOuter){ this.rOuter = rOuter; }

// getRadius, setRadius for using annulus with rInner = 0 as a circle

  public double getRadius() { return rOuter; }
  public void setRadius(double radius) { 
    this.rInner = 0;
    this.rOuter = radius; 
  }


}