Because it has four equal sides

rotation symentry-4
total degree of 180

4
180

90

Understanding Rotational Symmetry
Rotational symmetry refers to the property of a shape that looks the same after a certain amount of rotation. For a square, this means it can be rotated around its center without changing its appearance.

Square's Characteristics
- A square has four equal sides and four equal angles (90 degrees each).
- The square's vertices are positioned symmetrically around its center.

Rotational Symmetry of Square
- A square exhibits rotational symmetry at specific angles:
- 0 degrees (no rotation)
- 90 degrees
- 180 degrees
- 270 degrees

Why 90 Degrees?
- When a square is rotated by 90 degrees, each vertex moves to the position of another vertex:
- The top vertex moves to the right
- The right vertex moves to the bottom
- The bottom vertex moves to the left
- The left vertex moves to the top
- This transformation results in the square appearing unchanged, thus confirming its rotational symmetry at this angle.

Counting Rotational Symmetries
- A square has a total of four angles of rotational symmetry:
- 0 degrees (initial position)
- 90 degrees (first rotation)
- 180 degrees (upside-down)
- 270 degrees (three-quarters of a turn)

Conclusion
- The presence of rotational symmetry at 90 degrees is a fundamental property of squares, making them a classic example in geometry. Recognizing these transformations helps in understanding more complex geometric concepts.