Information about quizzes:

• On the date a quiz is given, a die will be thrown by a student in the class.
• Books and notes are put away.
• A question very similar to the chosen published question will be written on the board.
• You have 5 minutes to answer the question.

You will fare better on the quiz if you try working the problems before looking at the solutions. If you don't understand the question or its answer, please get help.

1. Provide an abstract class Stack for a stack that includes the operations isEmpty, push, and pop (you may find that other methods are needed). In the abstract class, make pop non-abstract. It should throw an error if the stack is empty, otherwise do a "real pop".
2. Subclass your Stack class into ListBasedStack that uses the List from class.
3. Subclass your Stack class into QueueBasedStack that uses the Queue structure presented in class.
4. Provide an abstract class for a Shape that includes methods for determinng the shape's area and circumference.
5. Subclass your Shape class into Rectangle.
6. Subclass your Rectangle class into Square.