What makes a good definition good? What makes a not-so-good definition not-so-good?
What would you say are the elements of fiction, or the elements of a novel?
Is a robin a better example of a bird than a penguin is? Why or why not?
What was a geometric object that was (or is) difficult to define?
In what ways can one geometric object be the same or different from another geometric object?
What are some good strategies for when you're feeling stuck on a problem?