On Triangles with Sides That Form an Arithmetic Progression

УДК 514.112.3

  • Yu.N. Maltsev Altai State Pedagogical University (Barnaul, Russia) Email: maltsevyn@gmail.com
  • A.S. Monastyreva Email: akuzmina1@yandex.ru
Keywords: triangle, circumradius, inradius, semiperimeter, arithmetic progression

Abstract

Properties of triangles such that the squares of their sides form an arithmetic progression were studied in 2018. In this paper, triangles with sides that form an arithmetic progression are described. Let a, b, c be sides of an arbitrary triangle ABC. If sides b, a, c of the triangle ABC form an arithmetic progression then, for example, the equality a=(b+c)/2 (b<a<c) holds. The class of triangles for which a=(b+c)/2 is greater than the class of triangles for which b, a, c form an arithmetic progression. In this paper, we study the properties of triangles for which this equality holds. Thus, triangles with sides that form an arithmetic progression are described with the help of the parameters p, R, r. Classes of rectangular triangles, triangles with angle 30°, triangles with angle 60°, triangles with angle 120° are studied and described.

Downloads

Download data is not yet available.

Metrics

Metrics Loading ...

Author Biographies

Yu.N. Maltsev, Altai State Pedagogical University (Barnaul, Russia)

доктор физико-математических наук, профессор кафедры алгебры и методики обучения математике

A.S. Monastyreva

доцент кафедры алгебры и математической логики Алтайского государственного университета

References

Bataille M. On the centres of root-mean-square triangles // Crux Mathematicorum. 2018. Vol. 44(2).

Lidskii V.B., Ovsyannikov L.V., Tulaykov A.N., Shabunin M.I. Tasks of elementary mathematics. M., 1965 (in Russian).

Scopec Z.A., Zharov V.A. Tasks and theorems of geometry. M., 1962 (in Russian).

Prasolov V.V. Tasks of plane geometry. M., 1986 (in Russian).

Galperin G.A., Tolpygo A.K. Moskow Mathematical Olympiadas. M., 1986 (in Russian).

Morozova E.A., Petrakov I.S. Internatiomal Mathematical Olympiadas. M., 1968 (in Russian).

Maltsev Yu.N., Monastyreva A.S. On Triangles Such That its Sides Form an Arithmetic Progression // Conference "Mathematics to Altai region"(Russia, Barnaul). 2019.

Soltan V., Maidman S. Identities and inequalities in a triangle. Kishinev, 1982 (in Russian).

Zetel S.I. New geometry of a triangle. M., 1962 (in Russian).

Maltsev Yu.N., Monastyreva A.S. Selected lectures on the geometry of triangle and quadrangle. Barnaul, 2016 (in Russian).

Published
2020-03-06
How to Cite
Maltsev Y., Monastyreva A. On Triangles with Sides That Form an Arithmetic Progression // Izvestiya of Altai State University, 2020, № 1(111). P. 111-114 DOI: 10.14258/izvasu(2020)1-18. URL: https://izvestiya.asu.ru/article/view/%282020%291-18.
Section
Математика и механика