What has two- fold rotational symmetry?

Two-fold rotational symmetry, also known as half-turn symmetry, occurs when an object can be rotated 180 degrees around a central point and appear unchanged. Common examples include a rectangle, where flipping it upside down results in the same shape, or a butterfly, which looks identical when rotated halfway around its center. This type of symmetry is present in many natural and man-made objects, including certain architectural designs and patterns.