Mentor: We call a polygon with three sides a triangle. Does anyone know what we call a polygon with four sides?
Student: A square?
Mentor: Well, a square is just one example. We call the whole family of four-sided polygons quadrilaterals. Can you think of other things that have four sides?
Student: A diamond--like the kind that you draw or a baseball diamond. They have four sides. Does that mean that a baseball diamond is a quadrilateral?
Mentor: Very good! That certainly is a quadrilateral.
Student: A door is a quadrilateral because it has four sides.
Mentor: Yes, any more?
Student: A piece of paper is a quadrilateral!
Student: A book!
Student: A computer monitor!
Student: A chess board or the chalk board!
Mentor: These are all wonderful answers. We should see how many quadrilaterals we see in our school and at home today.
Now we can talk about parallelograms!