The paper deals with architectural space designed and built on an equilateral triangular plan designated for a sacred function. The author discusses the exceptional features of an equilateral triangle compared to other central layouts. The visual attractiveness of this geometrical shape is stressed. The architectural space built on this figure has a solid semantic potential in Christian culture in Europe since a sacred object using such a shape is associated easily and unambiguously, which also points to the popularity of patrocinium of the Holy Trinity, as well as that of the Virgin and Child with St. Anne, among the analyzed structures. A comprehensive catalog of sacred objects based on an equilateral triangular plan, identified in the European culture area, was created between the 12th century and contemporary times. At the nexus of the Eastern and Western Church, which differentiate their teachings in terms of interpreting the Holy Trinity (the problem of Filioque), the patrocinium and the erection of temples in the form discussed here have a special meaning, mainly if these shrines belong to the Uniate Church, which merges Catholicism and the Orthodox church. The types of corner detailing have been analyzed.
  • What are Triangles? A triangle is a closed, 2-dimensional shape with three sides, three angles, and three vertices. A triangle is also a polygon. The above figure is a triangle denoted as △ABC.