It's just when you rotate a shape. Each time you rotate it, and it looks exactly like the shape you had before you started rotating, is one line of rotational symmetry.
Yes is a rotational symmetry 180 degree it will look like these
Because the London Eye can turn a full 360 degrees and replicate or look like itself it considered to have rotational symmetry.
The rectangle's rotational symmetry is of order 2. A square's rotational symmetry is of order 4; the triangle has a symmetry of order 3. Rotational symmetry is the number of times a figure can be rotated and still look the same as the original figure.
The rotational symmetry of a plane object is the number of times it will look exactly like its original shape when you rotate it through 360 degrees in its plane. A whole alphabet has no rotational symmetry but some letters in an alphabet may have rotational symmetry. The number of symmetries depends on the alphabet, whether the letters are in upper or lower case as well as the font used.
A trapezium does not have rotational symmetry.
The letters H and Z have both line symmetry and rotational symmetry
A shape like an equilateral triangle would therefore have an order of rotational symmetry of 3
It has 8lines of rotational symmetry
It has rotational symmetry to the order of 2
Equilateral triangles have rotational symmetry.
No a Z doesn't have a rotational symmetry
A trapezoid has no rotational symmetry.