class Circle {
  final static double PI=3.14;//聲明常量
  private static double dbRadius=1;//聲明公享變量
  public Circle(double radius){
    dbRadius=radius;
  }
  public double Area(){
    double area;
    area=PI*dbRadius*dbRadius;
    return area;
  }
  public static double Perimeter (){//添加靜態方法
    double perimeter ;
    perimeter=2*PI*dbRadius;
    return perimeter;
  }
}
public class CircleDemo1{
  public static void main(String[] args) {
    Circle cir=new Circle(3.5);
    //調用實例方法計算圓的面積
    System.out.println("圓的面積："+cir.Area());
    //調用靜態方法計算圓的周長
    System.out.println("圓的周長："+Circle.Perimeter());
  }
}