java求面积Shape类_Shape-2，形状类，正方形类，长方形类，圆类，求周长面积

[java]代码库import java.util.Scanner;

public class Main{

public static void main(String[] args) {

Scanner scan = new Scanner(System.in);

double length = scan.nextDouble();

Square s = new Square(length);

System.out.printf("%.2f ",s.getPerimeter());

System.out.printf("%.2f",s.getArea());

System.out.println();

length = scan.nextDouble();

double wide = scan.nextDouble();

Rectangle r = new Rectangle(length,wide);

System.out.printf("%.2f ",r.getPerimeter());

System.out.printf("%.2f",r.getArea());

System.out.println();

double radius = scan.nextDouble();

Circle c = new Circle (radius);

System.out.printf("%.2f ",c.getPerimeter());

System.out.printf("%.2f ",c.getArea());

scan.close();

}

}

class Shape

{

public double getPerimeter()

{

return 0;

}

public double getArea()

{

return 0;

}

}

class Square extends Shape

{

private double length;

public Square(double l)

{

length = l;

}

public double getLength()

{

return length;

}

public double getPerimeter()

{

return length*4;

}

public double getArea()

{

return length*length;

}

}

class Rectangle extends Square

{

private double wide;

public Rectangle(double l, double w)

{

super(l);

wide = w;

}

public double getPerimeter()

{

return (super.getLength()+wide)*2;

}

public double getArea()

{

return super.getLength()*wide;

}

}

class Circle extends Shape

{

private double r;

public Circle(double _r)

{

r = _r;

}

public double getPerimeter()

{

return 3.14159*r*2;

}

public double getArea()

{

return 3.14159*r*r;

}

}