/** A Circle using the Class Point */
public class Circle {
  private Point center;
  private double radius;
  
  // static final double PI = 3.14;
  private static final double PI = Math.PI;
  
  /** Default constructor */
  public Circle() {
    center = new Point();
    radius = 0;
  }
 

  /** Constructor */
  public Circle(double x, double y, double radius) {
    center = new Point(x,y);
    this.radius=radius;
  }
  
  /** Constructor */
  public Circle(Point center, double radius) {
    this.center = new Point(center);
    this.radius=radius;
  }
  
  /** Constructor with a center and a Point p on the perimeter*/
  public Circle(Point center, Point p) {
    this.center = new Point(center);
    this.radius=center.distance(p);
  }

 
  /** Returns the radius of circle */
  public double radius() {
    return (radius);
  }
 

  /** Returns the position of the center as a Point */
  public Point position() {
    return center;
  }
 
  /** Calculates the area */
  public double area() {
    return (radius*radius*PI);
  }

  /** Calculates the perimeter */
  public double perimeter() {
    return (2*radius*PI);
  }
  
  /** Converts the Circle to a String */ 
  public String toString() {
  return("Circle at " +  position() + " with radius="+radius);
  }

}