abstract class GeometricObject{
  private String color="yellow";
  private boolean filled;
  protected GeometricObject(){
  }
  protected GeometricObject(String color,boolean filled){
     this.color=color;
     this.filled=filled;
  }
  public String getColor(){
     return color;
  }
  public void setColor(){
     this.color=color;
  }
  public boolean isFilled(){
       return filled;
  }
  public void setFilled(boolean filled){
        this.filled=filled;
  }
  public abstract double getPerimeter();
}
  public class Triangle extends GeometricObject{
    private double side1;
    private double side2;
    private double side3;
    public Triangle(){
          this(1.0,1.0,1.0);
    }
    public Triangle(double side1,double side2,double side3){
      this(side1,side2,side3);
    }
    public double getSide1(){
         return side1;
    }
    public void setSide1(double side1){
        this.side1=side1;
    }
    public double getSide2(){
         return side2;
    }
    public void setSide2(double side2){
        this.side2=side2;
    }
    public double getSide3(){
         return side3;
    }
    public void setSide3(double side3){
        this.side3=side3;
    }
    public double getPerimeter(){
      return (side1+side2+side3)/2;
    }
    public double getArea(){
      return (Math.sqrt(getPerimeter()*(getPerimeter()-side1)*(getPerimeter()-side2)*(getPerimeter()-side3)));
    }
    public String toString(){
      return "Triangle:side1="+side1+"side2="+side2+"side3="+side3;
    }
}
public class TestRectangle{ 
  public static void main(String[] args){
    Triangle tri=new Triangle(1.0,1.5,1.0);
    System.out.println("該三角形的顏色為："+tri.getColor()+'\n');
    System.out.println("該三角形的周長為:"+tri.getPerimeter()+'\n');
    System.out.println("該三角形的面積為："+tri.getArea()+'\n');
    System.out.println("該三角形的填充為："+tri.isFilled()+'\n');
    System.out.println("該三角形的邊長為："+tri.toString()+'\n');

  } 
}