On
investigating all the letters of the English
alphabet for symmetry you may find:

letter symmetry often depends on the font you use
 some letters have no lines of symmetry
 some letters have one line of symmetry
 some letters have two lines of symmetry
 one letter has many lines of symmetry
 most letters do not have rotational symmetry
 a few have rotational symmetry of order two
 and 'O' is in a category of its own.
Letters 
Line
Symmetry  Number 
Rotational
Symmetry  Number 

No 
0 
Yes 
2 

No 
0 
Yes 
2 

Yes 
2 
Yes 
2 


Yes 
1 
No 
0 

No 
0 
Yes 
2 

Yes 
1 
No 
0 

Yes  Infinite  Yes  Infinite 
As
far as X goes you will find you need to argue a lot about
whether it has 2 lines of symmetry or 4.
The best way to stop the arguments is to do an investigation.
Type several Xs using different computer fonts, enlarged
them on a photocopier (or by typing a number larger than
72 in the size field), then cut them out and fold them.
What do you think you will find?
Go on, test it. You know you want to :)
