【交作文 】大家看看还需要哪些改进 小白求教@！！！

package com.imooc;

public abstract class Shape {

public abstract void hello (String girth,String area);

}

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package com.imooc;

public class Rectangle extends Shape {

@Override

public void hello(String girth,String area) {

// TODO Auto-generated method stub

System.out.println("矩形的周长是："+girth+"，面积是："+area);

}

}

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package com.imooc;

public class Circle extends Shape {

@Override

public void hello(String girth, String area) {

// TODO Auto-generated method stub

System.out.println("圆形的周长是："+girth+"，面积是："+area);

}

}

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package com.imooc;

public class Text {

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

Shape rec=new Rectangle();

rec.hello("2(a+b)", "a*b");//a为矩形的长，b为矩形的宽。

Shape cir=new Circle();

cir.hello("2Math.PIr","Math.PIr²" );

}

}

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矩形的周长是：2(a+b)，面积是：a*b

圆形的周长是：2Math.PIr，面积是：Math.PIr²