fig5_8printf.txt

用三个类来研究类的继承！类Point、Circle、Cylinder

编译的命令为：
	C:\tmp>bcc32 fig5_8.cpp circle2.cpp point2.cpp
	Borland C++ 5.6 for Win32 Copyright (c) 1993, 2002 Borland
	fig5_8.cpp:
	circle2.cpp:
	point2.cpp:
	Turbo Incremental Link 5.60 Copyright (c) 1997-2002 Borland

Y coodinate is 4.3
Radius is 2.5

The new location and radius of c are 
Center=[2, 2]; Radius=4.25
area:56.7

Circle print as a point is: [2.00, 2.00]