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!

JAVA程序设计导论 课后习题9。1 Modify the GeometricObject class to implement the -Enabling GeometricObject cmparable