Not many. Depending on how you write, the letters L, O, Q, and X can have diagonal lines of symmetry.
In caps there is 1. lower case none.
zero, all the keys have different letters, numbers, or symbols
the answer is U O S H K Z X N A D=2 0R MORE LINES OF SYMMETRY
2 lines OF SYMMETRY
Not many. Depending on how you write, the letters L, O, Q, and X can have diagonal lines of symmetry.
Pi has 2 lines of symmetry
None.
O and X And H and I (Note "O" has many, actually an infinite number of, lines of symmetry)
Five.H , I , O , X( ' O ' has 2 lines of symmetry and more besides and ' X ' has 4 )
H,I,O,X Note that if you draw "O" as a perfect circle, it will have infinitely many lines of symmetry.
Seven
None. Some letters have one or more but all the letters, taken as a set, have none.
In caps there is 1. lower case none.
zero, all the keys have different letters, numbers, or symbols
the answer is U O S H K Z X N A D=2 0R MORE LINES OF SYMMETRY
A nephroid has 2 lines of symmetry.