What is the order of rotational symmetry for a rhombus?

1

2

3

4

In general, a rhombus' diagonals have different lengths. This limits the rotational symmetry order to be 2, namely, it gets back to the same shape by rotating 180 degrees.

There is a special kind of rhombus where the diagonals have equal lengths, in which case the rhombus has order of rotational symmetry of four. We also call this special kind of rhombus a square.