the quality of having parts that match each other, especially in a way that is attractive, or similarity of shape or contents
The design of the house had a pleasing symmetry, its oblong shape being picked up in its elongated windows.房子的设计透着一种赏心悦目的对称美，狭长的窗户使长方形的结构显得更加和谐。
Compare: asymmetry(asymmetric)
mathematicsspecialized（数学中的）对称（性）
in mathematics, the quality of having two parts that match exactly, either when one half is like an image of the other half in a mirror, or when one part can take the place of another if it is turned 90° or 180°