Halfturn Symmetry

Look at the letter S below.
Imagine poking a pin in the center and spinning the picture around the pin until it is upside down. What does it look like?
It looks the same as before!

Now, If we cut the picture in half through the pin hole and turn one piece a halfturn (180 degrees), we get two identical pieces.


If a picture can be turned a halfturn and still look the same, then we say that the picture has halfturn symmetry. The place where we cut the picture through the pin hole is called the line of halfturn symmetry. Draw a line of halfturn symmetry for each of these pictures:

          N          O                    

Actually, for each of the above pictures, there are many places you can draw a line of half turn symmetry. Draw at least 3 more for the first two pictures above.