sümmeetriakeset

The term sümmeetriakeset, derived from Finnish, translates to "center of symmetry." In geometry, a center of symmetry is a point such that for every point on an object, there is a corresponding point on the object such that the center of symmetry is the midpoint of the line segment connecting these two points. Essentially, if you rotate an object 180 degrees around its center of symmetry, it will look exactly the same as it did before the rotation.

Not all geometric shapes possess a center of symmetry. For example, a triangle generally does not have a center of symmetry, unless it is an equilateral triangle, in which case the centroid, circumcenter, and incenter coincide and act as the center of symmetry. Squares, rectangles, circles, and regular polygons with an even number of sides all have a center of symmetry. For figures with a center of symmetry, it is a unique point. The concept is also applicable to three-dimensional objects, where the center of symmetry remains invariant under a point reflection.