Department of Mathematics and Computing
York College (CUNY)
Jamaica, New York 11451
1. What is the name of the object shown:
2. Are there other objects which are different from the one above but
for which you would use the same name?
3. Write down a list of as many properties (facts about) the object
Question 1 as you can.
(Unless your list contains at least 25 items you have not looked at the
object as carefully as you might. However, it takes practice to look
at a geometric object as carefully as we are aiming for.)
4. How would you describe the object in Question 1 over the phone to a
friend? (or to an intelligent alien!)
5. Why do mathematicians care about giving precise definitions of the
technical terms used in mathematics?
6. Think about how you would define the terms you use to describe the
properties of the object in Question 1.
7. Can you give examples of words whose technical meaning in mathematics
is not the same as the meaning these words have in everyday use?
8. What are the pros and cons of requiring great precision in