public class Circle extends Shape{
   private double radius;

   public Circle() {
      super();
      this.radius = 1.0;
   }

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

   public Circle(double radius,boolean isFilled,String color){
      super(isFilled, color);
      this.radius = radius;
   }

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

   public double getRadius() {
      return this.radius;
   }

   public String toString() {
      String ret = "";
      ret += "Radius: " + this.radius + "\n";
      double area = Math.PI * Math.pow(this.radius,2);
      ret += "Area: " + area + "\n";
      ret += super.toString();
      return ret;
   }
}