The letter "Z" has two lines of rotational symmetry. When rotated 180 degrees, it looks the same, but it does not have any other angles at which it maintains its appearance. Thus, it exhibits rotational symmetry only at this specific angle.
No a Z doesn't have a rotational symmetry
z
It has rotational symmetry.
The letters S, N, Z, for example.
Nothing. (Except if you count z axis and you get into 3D!)
No a Z doesn't have a rotational symmetry
The letters H and Z have both line symmetry and rotational symmetry
I, H, N, O, S, X & Z all have rotational symmetry.
Order 2.
Yes is a rotational symmetry 180 degree it will look like these
z
It has rotational symmetry.
It has a line of rotational symmetry - along the diagonal.
The letters S, N, Z, for example.
Z S H and N
Depending on the font, they are N, S and Z.
Nothing. (Except if you count z axis and you get into 3D!)