//areacircle.java
import java.io.*;
abstract class Areacircle {
	public abstract double area();
	public abstract double perimeter();
	
}

class Line extends Areacircle{ 
	double x1;
	double x2;
	double y1;
	double y2;
	public Line(double x1,double x2,double y1,double y2){
		this.x1 = x1;
		this.x2 = x2;
		this.y1 = y1;
		this.y2 = y2;
	}


	@Override
	public double area() {
		// TODO Auto-generated method stub
		System.out.println("the line's has no area!");
		return 0;
	}

	@Override
	public double perimeter() {
		// TODO Auto-generated method stub
		System.out.println("the line's circle is infinity!");
		return 0;
	}
	
	
}

class Circle extends Areacircle{
	double x;
	double y;
	double radium;
	public Circle(double x,double y,double radium){
		this.x = x;
		this.y = y;
		this.radium = radium;
	}
	@Override
	public double area() {
		// TODO Auto-generated method stub	
		return Math.PI*radium*radium;
	}

	@Override
	public double perimeter() {
		// TODO Auto-generated method stub
		return 2*Math.PI*radium;
	}
	
    public void center(double x,double y){
		x = this.x;
		y = this.y;
	}
	
}

class Triangle extends Areacircle{
	double x1;
	double x2;
	double x3;
	double y1;
	double y2;
	double y3;
	public Triangle(double x1,double x2,double x3,double y1,double y2,double y3){
		this.x1 = x1;
		this.x2 = x2;
		this.x3 = x3;
		this.y1 = y1;
		this.y2 = y2;
		this.y3 = y3;
	}
	
	@Override
	public double perimeter() {
		// TODO Auto-generated method stub
		return Math.sqrt((this.x1-this.x2)*(this.x1-this.x2)+(this.y1-this.y2)*(this.y1-this.y2))+Math.sqrt((this.x3-this.x2)*(this.x3-this.x2)+(this.y1-this.y2)*(this.y3-this.y2))+Math.sqrt((this.x1-this.x3)*(this.x1-this.x3)+(this.y1-this.y3)*(this.y1-this.y3));				
		
	}
	
	@Override
	public double area() {
		// TODO Auto-generated method stub
		double d =this.perimeter()*0.5;
		return Math.sqrt(d*(d-Math.sqrt((this.x1-this.x3)*(this.x1-this.x3)+(this.y1-this.y3)*(this.y1-this.y3)))*(d-Math.sqrt((this.x3-this.x2)*(this.x3-this.x2)+(this.y3-this.y2)*(this.y3-this.y2)))*(d-Math.sqrt((this.x1-this.x2)*(this.x1-this.x2)+(this.y1-this.y2)*(this.y1-this.y2))));
	
	}
	
    public void center(double x,double y){
		x = (x1 + x2 + x3)/3;
		y = (y1 + y2 + y3)/3;
	}
	
}

class Rectangle extends Areacircle{
	double x1;
	double x2;
	double x3;
	double y1;
	double y2;
	double y3;
	double x4;
	double y4;
	public Rectangle(double x1,double x2,double x3,double x4,double y1,double y2,double y3,double y4){
		this.x1 = x1;
		this.x2 = x2;
		this.x3 = x3;
		this.y1 = y1;
		this.y2 = y2;
		this.y3 = y3;
		this.x4 = x4;
	}
	@Override
	public double area() {
		// TODO Auto-generated method stub
		return Math.sqrt(this.x1 - this.y1)*(this.x1 - this.y1)+(this.x1 - this.y1)*(this.x3 - this.y3);
	}

	@Override
	public double perimeter() {
		// TODO Auto-generated method stub
		return 2*(Math.sqrt((x1-x2)*(x1 - x2)+(y1 - y2)*(y1 - y2))+Math.sqrt((x1-x3)*(x1 - x3)+(y1 - y3)*(y1 - y3)));
	}
	
    public void center(double x,double y){
		x = (x1 +x2)/2;
		y = (y1 +y3)/2;
	}

}
public class Graphics
{
	public double distance(Triangle g1,Circle g2){
		int x1= 0,y1 = 0,x2 = 0,y2 = 0;
		g1.center(x1,y1);
		g2.center(x2,y2);
		return Math.sqrt((x1-x2)*(x1 - x2)+(y1 - y2)*(y1 - y2));
	}
	public static void main(String[] args){
		
		
		Triangle t1 = new Triangle(1,1,2,1,2,1);
		Circle c1 = new Circle(3,1,1);
		System.out.println("The triangle t1's area is "+t1.area()+",and the perimeter is "+t1.perimeter());
		System.out.println("The circle c1's area is "+c1.area()+",and the perimeter is "+c1.perimeter());
	}
	
}