The document defines a polygon as a closed figure made of line segments that intersect exactly two other segments. It provides examples of polygons and non-polygons, explaining why figures are or aren't polygons based on whether they are closed, composed of line segments, or have sides that intersect more than twice. The document concludes with an activity for students to identify polygons and non-polygons in a math book.

1. Unit 4 Quadrilaterals and Polygons

2. A polygon is a closed figure made by
joining line segments, where each line
segment intersects exactly two others.

3. These are examples
of polygons.

4. This, however, is not a polygon.
Why
not?

5. It isn’t a polygon because it isn’t a
closed figure.
Now it’s a
polygon!

6. This is not a polygon.
Why
not?

7. This figure isn’t a polygon
because it is not made of line
segments.
This is a
line
segment.

8. This figure isn’t a polygon.

9. This figure isn’t a polygon
because its sides do not intersect
in exactly two places each.
This line
intersects
with other
lines in 3
places.

10. Hold up your left hand if you see a
polygon.
Hold up your right hand if you see
something that isn’t a polygon.

19.  Let’s do page # 46 in your math books.
Look at the picture and write YES if you
see a polygon or NO if you don’t.