# Symmetry

Examples of symmetry in shapes.
Diatoms, a kind of algae, are symmetric
Leonardo da Vinci's Vitruvian Man (ca. 1487) is often used as a representation of symmetry in the human body and, by extension, the natural universe.
Symmetric arcades of a portico in the Great Mosque of Kairouan also called the Mosque of Uqba, in Tunisia.

Symmetry is a property that certain geometrical objects have. If the objects are symmetric, this means that the object appears the same (to be mirrored or reflected) along an axis. This axis has to cross the shape through the middle.

The precise notions of symmetry have various measures and operational definitions. For example, symmetry may be observed

## References

1. For example, operations such as moving across a regularly patterned tile floor or rotating an eight-sided vase, or in the way music is played.
2. See, e.g., Mainzer, Klaus (2005). Symmetry and complexity: the spirit and beauty of nonlinear science. World Scientific. .
3. Symmetric objects can be material, such as a person, crystal, quilt, floor tiles, or molecule, or it can be an abstract structure such as a mathematical equation or a series of tones (music).

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