Characterization of extremal antipodal polygons

O. Aichholzer, L. Caraballo, J. Díaz-Báñez, R. Fabila-Monroy, C. Ochoa, and P. Nigsch

Abstract:

Let $S$ be a set of $2n$ points on a circle such that for each point $p \in S$ also its antipodal (mirrored with respect to the circle center) point $p'$ belongs to $S$. A polygon $P$ of size $n$ is called antipodal if it consists of precisely one point of each antipodal pair $(p,p')$ of $S$. We provide a complete characterization of antipodal polygons which maximize (minimize, respectively) the area among all antipodal polygons of $S$. Based on this characterization, a simple linear time algorithm is presented for computing extremal antipodal polygons. Moreover, for the generalization of antipodal polygons to higher dimensions we show that a similar characterization does not exist.



Reference: O. Aichholzer, L. Caraballo, J. Díaz-Báñez, R. Fabila-Monroy, C. Ochoa, and P. Nigsch. Characterization of extremal antipodal polygons. Graphs and Combinatorics, 31:321-333, 2015.

www-data, 2020-09-10