package tuxing2;

public abstract class tuxing {

    static int a = 4;

    static double π = 3.14;

    static int b = 5;

public abstract void Area();//面积

    public abstract void Perimeter();//周长

}

-----------------------------------------------------------------------------------------------------------------------------------------------

package tuxing2;

public class Round extends tuxing {

@Override

public void Area() {//圆形的面积

// TODO Auto-generated method stub

        System.out.println("圆形的面积= "+π*a*a);

}

@Override

public void Perimeter() {//圆形的周长

// TODO Auto-generated method stub

System.out.println("圆形的周长= "+2*π*a);

}

}

-----------------------------------------------------------------------------------------------------------------------------------------------

package tuxing2;

public class Rectangle extends tuxing {

@Override

public void Area() {//矩形的面积

// TODO Auto-generated method stub

System.out.println("矩形的面积= "+a*b);

}

@Override

public void Perimeter() {//矩形的周长

// TODO Auto-generated method stub

System.out.println("矩形的周长= "+(a+a+b+b));

}

}

-----------------------------------------------------------------------------------------------------------------------------------------------

package tuxing2;

public class Test {

public static void main(String[] args) {

// TODO Auto-generated method stub

tuxing TX1 = new Round();

TX1.Area();

TX1.Perimeter();

tuxing TX2 = new Rectangle();

TX2.Area();

TX2.Perimeter();

}

}