用java实现棱形的程序！并且其它的形状可以从它继承！在机子上编绎并通过！很实用！-java achieve a rhombus with the procedure! And the other from its shape can be inherited! On the loom and through continuous series! Very practical!

According to the Oxford English Dictionary, the first known historical meaning of the word information in English was the act of informing, or giving form or shape to the mind, as in education, instruction, or training. A quote from 1387: "Five books

Step1: 为实验3中定义的矩形类派生一个子类：正方形类。正方形类的操作同样是求周长和面积。则这个子类除了从父类继承来的方法之外，还需要定义哪些方法？列出正方形类的所有域与方法。编程验证所编写的正方形类。 Step2: 定义接口Printable，其中包括一个方法printItMyWay()，这个方法没有形参，返回值为空。 Step3: 改写矩形类使之实现Printable接口，用printItMyWay()方法将矩形的相关信息（长，宽，周长，面积）打印在屏幕上。 S