Note: Strictly speaking, a polygon does not include its interior (the space inside the polygon).
a polygon  not closed; not a polygon 
not made of line segments; not a polygon 
line segment intersects more than two others; not a polygon 
Polygons are usually classified according to how many sides they have:
A triangle is a polygon with $\,3\,$ sides.  A heptagon is a polygon with $\,7\,$ sides.  
A quadrilateral is a polygon with $\,4\,$ sides.  An octagon is a polygon with $\,8\,$ sides.  
A pentagon is a polygon with $\,5\,$ sides.  A nonagon is a polygon with $\,9\,$ sides.  
A hexagon is a polygon with $\,6\,$ sides.  A decagon is a polygon with $\,10\,$ sides. 
More generally, a polygon with $\,n\,$ sides can be called an $\,n\,$gon.
For example, a polygon with $\,27\,$ sides can be called a $\,27$gon.
When naming polygons, the vertices must be listed in consecutive order. For example, the polygon at right could be named:

More generally, when naming an $\,n$gon, there are $\,n\,$ choices for listing the first vertex.
Then, there are $\,2\,$ choices for the next vertex (moving clockwise or counterclockwise).
The remaining vertices are then completely determined.
Thus, there are $\,2n\,$ choices for the polygon name.
a regular triangle  a regular quadrilateral (a square) 
a regular pentagon  a regular hexagon 
a regular heptagon  a regular octagon  a regular nonagon  a regular decagon 
Note: Every square is a rectangle.
However, not every rectangle is a square.
That is, there exist rectangles that are not squares.
each of these is a rectangle, but NOT a square 
For fun, jump up to WolframAlpha and type in (say)
‘triangle’ or ‘quadrilateral’.
You'll get loads of information!
On this exercise, you will not key in your answer. However, you can check to see if your answer is correct. 
PROBLEM TYPES:
