Unified Constructions of the Regular Heptagon and Triskaidecagon

Helmut Ruhland

doi:10.32603/2071-2340-2025-1-27-32

Helmut Ruhland Independent Researcher, Calle 282, #1104, Santa Fe, La Habana, Cuba

DOI: https://doi.org/10.32603/2071-2340-2025-1-27-32

Keywords: geometric construction, trisection, heptagon, triskaidecagon, tridecagon

Abstract

Constructions of regular heptagon and triskaidecagon by trisection of an angle are well known. An elegant construction of the heptagon by S. Adlaj shows a 3-fold symmetry related to a Galois group. Based on the latter construction, in this article one more for the heptagon and two more for the triskaidecagon are presented, all using angle trisection.

Author Biography

Helmut Ruhland, Independent Researcher, Calle 282, #1104, Santa Fe, La Habana, Cuba

MSc, Independent Researcher, Cuba, helmut.ruhland50@web.de

References

A. Gleason, “Angle Trisection, the Heptagona, and the Triskaidecagon,” The American Mathematical Monthly, vol. 95, no. 3, pp. 185–194, 1988; doi:10.2307/2323624

S. Adlaj, “The Heptagon constructed!,” in semjonadlaj.com, 2024. [Online]. Available: https://SemjonAdlaj.com/Excerpts/Heptagon.pdf