original_query: What is a point reflection in geometry?
query: What is a point reflection in geometry?
answer: In geometry, a point reflection, also known as inversion in a point or central inversion, is a type of isometry of Euclidean space.  An object invariant under point reflection has point symmetry; if invariant through its center, it has central symmetry. It's an isometric involutive affine transformation with one fixed point (the point of inversion) and is equivalent to a homothetic transformation with a scale factor of -1.