//package oop123;              //包
import java.io.*;              //引入键盘输入所需要的类所在的包
interface getProperty{         //接口定义，方法声明
	double Pi = 3.1415926;
	double getArea();          //面积
	double getCircum();        //周长
	String getName();          //名称
}

class mpoint{                  //定义点
	static int i = 0;
	double x,y;
	mpoint(double a,double b){
		this.x = a;
		this.y = b;
	}
	double getX(){
		return x;
	}
	double getY(){
		return y;
	}

}

class disp{                  //定义屏幕输出所需要的类
	double area;             //面积
	double circum;           //周长
	String drawingName;      //名称
	disp(double a,double b,String ss){
		this.area = a;
		this.circum = b;
		this.drawingName = ss;
	}
	public void display(){
		System.out.println("图像 是 "+ drawingName);
		System.out.println("面积 = "+area+'\n'+"周长 = "+circum);
	}
}

class triangle implements getProperty{    //定义三角形
	mpoint p1,p2,p3;                      //三点
	double s1,s2,s3;                      //三边 
	String drawingName = "triangle";
	triangle(mpoint p1,mpoint p2, mpoint p3){ //构造方法
		this.p1 = p1;
		this.p2 = p2;
		this.p3 = p3;
		this.s1 = Math.sqrt((p1.x - p2.x)*(p1.x - p2.x)+(p1.y-p2.y)*(p1.y-p2.y));
		this.s2 = Math.sqrt((p3.x - p2.x)*(p3.x - p2.x)+(p3.y-p2.y)*(p3.y-p2.y));
		this.s3 = Math.sqrt((p1.x - p3.x)*(p1.x - p3.x)+(p1.y-p3.y)*(p1.y-p3.y));
	}
	 //方法实现
	public double getArea(){      
		double ss,ssa;
		ss = (s1+s2+s3)*Pi/2.0/Pi;
		ssa = Math.sqrt(ss*(ss-s1)*(ss-s2)*(ss-s3));
		return ssa;
	}
	public double getCircum(){
		return s1+s2+s3;
	}
	public String getName(){
        return drawingName;
	}
	public boolean tline(){
		return true;
	}
}

class circle implements getProperty{     //定义圆形
	mpoint p1;                           //圆心
	double radius;                       //半径
	String drawingName = "Circle";
	circle(mpoint p1,double radius){    //构造方法
		this.p1 = p1;
		this.radius = radius;
	}
	public double getArea(){
		double ssa;
		ssa = Math.PI*radius*radius;
		return ssa;
	}
	public double getCircum(){
		return Math.PI*2.0*radius;
	}
	public String getName(){
		return drawingName;
	}
	public boolean tcircle(){
		return true;
	}
}

class rectangle implements getProperty{   //定义长方形
	mpoint p1,p2;
	double s1,s2;
	String drawingName = "Rectangle";
	rectangle(mpoint p1,mpoint p2){
		this.p1 = p1;
		this.p2 = p2;
		this.s1 = Math.sqrt((p1.x-p2.x)*(p1.x-p2.x));
		this.s2 = Math.sqrt((p1.y-p2.y)*(p1.y-p2.y));
	}
	public double getArea(){
		return s1*s2;	
	}
	public double getCircum(){
		return s1+s2+s1+s2;
	}
	public String getName(){
		return drawingName;
	}
	public boolean rline(){
		return true;
	}
}
public class drawing extends disp{      //定义 main() 所在的类
	drawing (double a, double b, String ss){
		super(a,b,ss);
//由于子类不能继承父类的构造方法，因此，如果要调用父类的构造方法，
//可以使用 super 关键字。super 可以用来访问父类的构造方法、普通方法和属性。
	}
	public static void main(String[] args) throws IOException {
         BufferedReader keyin = new BufferedReader(new InputStreamReader(System.in));
//new BufferedReader 将字符流放到字符流缓冲区之中
//new InputStreamReader 将字节流变为字符流
//System.in 字节输入流
         String strxx;
         for(;true;){
         	System.out.println("输入字符串如 Triangle,Rectangle,Circle:");
         	strxx = keyin.readLine();  //读取输入
         	if(strxx.length() == 0) continue;
         	char charxx;
         	charxx = strxx.toUpperCase().charAt(0);  //大小写转换
         	switch(charxx)
         	{
             	case'T':         //三角形
             	System.out.println("请输入(三角形) 第一个点 x(enter) y(enter)");
             	mpoint p1 = new mpoint(aVar(keyin),aVar(keyin));
             	System.out.println("请输入(三角形) 第二个点 x(enter) y(enter)");
             	mpoint p2 = new mpoint(aVar(keyin),aVar(keyin));
             	System.out.println("请输入(三角形) 第三个点 x(enter) y(enter)");
             	mpoint p3 = new mpoint(aVar(keyin),aVar(keyin));
             	triangle t1 = new triangle(p1,p2,p3);  //构造三角形
             	disp tdisp = new drawing(t1.getArea(),t1.getCircum(),t1.getName());
             	tdisp.display();
             	break;
             	
             	case'C':        //圆形
             	System.out.println("请输入(圆形) 圆心 x(enter) y(enter)");
             	mpoint p4 = new mpoint(aVar(keyin),aVar(keyin));
             	System.out.println("请输入半径 x(enter)");
             	double radius = aVar(keyin);
             	circle t2 = new circle(p4,radius);   //构造圆形
             	disp cdisp = new drawing(t2.getArea(),t2.getCircum(),t2.getName());
             	cdisp.display();
             	break;
             	
             	case'R':        //长方形
                System.out.println("请输入(长方形)第一个点 x(enter) y(enter)");
                mpoint p6 = new mpoint(aVar(keyin),aVar(keyin));
                System.out.println("请输入(长方形)第一个点 x(enter) y(enter)");
                mpoint p7 = new mpoint(aVar(keyin),aVar(keyin));
                rectangle t3 = new rectangle(p6,p7);   //构造长方形
                disp rdisp = new drawing(t3.getArea(),t3.getCircum(),t3.getName());
                rdisp.display();
                break;
                
                default:System.out.println("错误，请输入 t(T),c(C),r(R)");
         	}//switch
         }//for循环
	}//main 方法
	static double aVar(BufferedReader keyin) throws IOException
	{//得到一个双变量
		String xx;
		xx = keyin.readLine();
		return Double.parseDouble(xx);

	}
}