Ninja Thank you for answer,
I think i couldnt explain question clearly;
As a question;
1. r and h have to input from keyboard but you gave value them and as double.
2. r and h can input from keyboard and may be integer, double or float so that calculation of volume() and area() can give permission to the polymorphism.
3.Area() and Volume() functions must be declared as a class of member functions.
I would like to thank to the nuzzle and 2kaud too.