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Ò»¡¢¼ÆËãÔ²µÄÃæ»ýµÄcalArea£¨£©·½·¨£»
¶þ¡¢¼ÆËãÖܳ¤µÄcalLength£¨£©·½·¨£»
Èý¡¢boolean inCircle£¨MyPoint mp£©·½·¨£¬¹¦ÄÜÊDzâÊÔ×÷Ϊ²ÎÊýµÄij¸öµãÊÇ·ñÔÚµ±Ç°¶ÔÏóÔ²ÄÚ£¨Ô²ÄÚ£¬°üÀ¨Ô²ÉÏ·µ»Øtrue£¬ÔÚÔ²Íâ·µ»Øfalse£©¡£
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class MyPoint{
  private int x,y;
  public void setX(int x){
   this.x=x;
  }
  public int getX(){
  return this.x;
  }
  public void setY(int y){
   this.y=y;
  }
  public int getY(){
  return this.y;
  }
  public String toString(){
   String str="("+this.x+","+this.y+")";
   return str;
  }
}
class Circle {
 private MyPoint myPoint=null;
 private double radius=0.0;
 public Circle(MyPoint myPoint,int radius){
 this.myPoint=myPoint;
 this.radius=radius;
 }
 public double calArea(){
  return Math.PI*radius*radius;
 }
 public double calLength(){
  return 2*Math.PI*radius;
 }
 public boolean inCircle(MyPoint mp){
  double a=Math.sqrt(Math.pow(mp.getX()-myPoint.getY(),2)+Math.pow(mp.getY()-myPoint.getY(),2));
 if(a>radius){
 return false;
 }
 return true;
 }
}
public class T14{
 public static void main(String args[]){
  MyPoint mp=new MyPoint();
  mp.setX(0);
  mp.setY(0);
  Circle c=new Circle(mp,5);
  double area=c.calArea();
  double length=c.calLength();
  MyPoint mp2=new MyPoint();
  mp2.setX(3);
  mp2.setY(3);
  boolean in=c.inCircle(mp2);
  System.out.println("area="+area+",length="+length+",inCircle="+in);
 
 }
}
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