Symmetry

1. the correspondence in size, form, and arrangement of parts on opposite sides of a plane,
line, or point; regularity of form or arrangement in terms of like, reciprocal,
or corresponding parts.

2. the proper or due proportion of the parts of a body or whole to one another with regard
to size and form; excellence of proportion.

3. beauty based on or characterized by such excellence of proportion.

from dictionary.com