sh-2.02$ cxx -lm pgm13-8.cpp
sh-2.02$ a.out

The area of circle_1 is 3.14159
The area of circle_2 is 12.5664
The volume of cylinder_1 is 113.097

The area of circle_1 is now 28.2743

sh-2.02$ cxx -lm pgm13-9.cpp
sh-2.02$ a.out
The computed value using a base class object call is 36
The computed value using a derived class object call is 36
sh-2.02$ exit
exit