来来来交作业

package homework;
public abstract class shape {	
    public abstract void perimeter();		
    public abstract void area();
    }

public class Rectangle extends shape {

int h = 5;

int w = 3;

public void perimeter() {

System.out.println("矩形周长为:"+2*(h+w));

}

@Override

public void area() {

System.out.println("矩形面积为:"+(h*w));

}

}

public class Circle extends shape {

float r = 3.2f; 

float π = 3.14f;

@Override

public void perimeter() {

System.out.println("圆周长为:"+2*π*r);

}

@Override

public void area() {

System.out.println("圆面积为:"+r*π*r);

}

}

public class test {

public static void main(String[] args) {

Rectangle re = new Rectangle();

re.perimeter();

re.area();

Circle ci = new Circle();

ci.area();

ci.perimeter();

}

}