1.　　将点-圆 柱的继承关系用类表示出来。

创建Point类、Circle类和Cylinder类

创建使用该三个类的主类。

注意：每个类至少有两个构造函数和三个方法。

- point- round- cylindrical inheritance relationship with class said.

Create class Point, Circle, Cylinder class

Created using the three main classes.

Note: Each class has at least two constructor and three methods.