A generalisation of the Steiner – Lehmus theorem and critical values transcendence of its parameters

Authors

  • Maksim M. Vaskouski Belarusian State University, 4 Niezaliezhnasci Avenue, Minsk 220030, Belarus
  • Maksim A. Firsau Belarusian State University, 4 Niezaliezhnasci Avenue, Minsk 220030, Belarus
  • Palina D. Babayeva Belarusian State University, 4 Niezaliezhnasci Avenue, Minsk 220030, Belarus

Keywords:

internal n-line of a triangle, transcendental number, algebraic number field, surface

Abstract

The internal n-line of a triangle is a segment from the vertex to the opposite side dividing this side into segments proportionally to the nth powers of the adjacent sides. An analogue of the Steiner – Lehmus theorem for the internal n-lines of a triangle is considered. All values n ∈ R for which the mentioned analogue of the Steiner – Lehmus theorem holds are found. Also all values n ∈ R for which there exists a non-equilateral triangle with three equal internal n-lines are determined. The transcendence of positive critical values of n of the generalised Steiner – Lehmus theorem is proved.

Author Biographies

  • Maksim M. Vaskouski, Belarusian State University, 4 Niezaliezhnasci Avenue, Minsk 220030, Belarus

    doctor of science (physics and mathematics), full professor; head of the department of fundamental mathematics and intelligence systems, faculty of applied mathematics and computer science

  • Maksim A. Firsau, Belarusian State University, 4 Niezaliezhnasci Avenue, Minsk 220030, Belarus

    assistant at the department of fundamental mathematics and intelligence systems, faculty of applied mathematics and computer science

  • Palina D. Babayeva, Belarusian State University, 4 Niezaliezhnasci Avenue, Minsk 220030, Belarus

    student at the faculty of applied mathematics and computer science

References

  1. Coxeter HSM, Greitzer SL. Geometry revisited. Washington: Mathematical Association of America; 1967. The Steiner – Lehmus theorem; p. 14–16 (New mathematical library; volume 19).
  2. Pambuccian V. Negation-free and contradiction-free proof of the Steiner – Lehmus theorem. Notre Dame Journal of Formal Logic. 2018;59(1):75–90. DOI: 10.1215/00294527-2017-0019.
  3. Kellison A. A machine-checked direct proof of the Steiner – Lehmus theorem. In: Association for Computing Machinery. CPP2022. Proceedings of the 11th ACM SIGPLAN International conference on certified programs and proofs; 2022 January 17–18; Philadelphia, USA. New York: Association for Computing Machinery; 2022. p. 265–273. DOI: 10.1145/3497775.3503682.
  4. Pambuccian V, Struve H, Struve R. The Steiner – Lehmus theorem and «triangles with congruent medians are isosceles» hold in weak geometries. Beiträge zur Algebra und Geometrie. 2016;57:483–497. DOI: 10.1007/s13366-015-0278-y.
  5. Vaskouski M, Kastsevich K. New signs of isosceles triangles. International Journal of Geometry. 2013;2(2):56–67.
  6. Strzeboński A. Real root isolation for exp-log-arctan functions. Journal of Symbolic Computation. 2012;47(3):282–314. DOI: 10.1016/j.jsc.2011.11.004.
  7. Frank WL. Finding zeros of arbitrary functions. Journal of the ACM. 1958;5(2):154–160. DOI: 10.1145/320924.320928.
  8. Gelfond A. Sur le septième problème de Hilbert. Bulletin de l’Académie des sciences de l’URSS. Classe des sciences mathématiques et neturelles. Série 7. 1934;4:623–634.

Downloads

Published

2025-11-11

Issue

Section

Mathematical Logic, Algebra and Number Theory

How to Cite

[1]
Vaskouski, M.M. et al. 2025. A generalisation of the Steiner – Lehmus theorem and critical values transcendence of its parameters. Journal of the Belarusian State University. Mathematics and Informatics. 2 (Nov. 2025), 42–61. DOI:https://doi.org/10.33581/2520-6508-2025-2-42-61.