The Kariya problem and related constructions - Paul Yiu Given a point Q other than the incenter I of a reference triangle, we give a simple conic...
Pairs of cocentroidal inscribed and circumscribed triangles - Gotthard Weise Let T be a reference triangle and P a point not on the sidelines. We...
Reciprocal Jacobi triangles and the McCay cubic - Glenn T. Vickers Given a triangle and a set of three angles, the celebrated geometrical theorem...
Points on a line that maximize and minimize the ratio of the distances to two given points - Arie Bialostocki and Rob Ely Given a line L and...
Another construction of the Simson lines through a given point - Francisco Javier Garcia Capitan We give a simple conic construction of the...
On a flawed, 16th-century derivation of Brahmagupta's formula for the area of a cyclic quadrilateral - Eisso Atzema Around 1545, the Indian...
Do dogs play with rulers and compasses - Li Zhou A dog runs at the speed of 1 and swims at the speed of s<1. If the dog is at point A on the...
About two characteristic points concerning two nested circles and their use in research of bicentric polygons - Mirko Radic This paper is a...
Another archimedean circle in an arbelos - Emmanuel Antonio Jose Garcia The incircle of a triangle associated with an arbelos is Archimedean....
Lemniscates and a locus related to a pair of median and symmedian - Francisco Javier Garcia Capitan We show that the lemniscate of Bernoulli...
Two conjectures of Victor Thebault linking tetrahedra with quadrics - Blas Herrera We prove two of Thebault's conjectures. The first (1949) links...
Equilateral triangles and Kiepert perspectors in complex numbers - Dao Thanh Oai We construct two equilateral triangles associated with an...
Bounds for elements of a triangle expressed by R, r, s - Temistocle Birsan Assume that a triangle is defined by the triple (R,r,s) fulfilling...
Reflections on Poncelet's pencil - Roger C. Alperin We illustrate properties of the conics in Poncelet's pencil using some new insights motivated...
The golden section in the inscribed square of an isosceles right triangle - Tran Quang Hung We prove the occurrence of the golden section with...
From electrostatic potentials to yet another triangle center - Hrvoje Abraham and Vjekoslav Kovac We study the problem of finding a point of...
Volumes of solids swept tangentially around general surfaces - Tom M. Apostol and Mamikon A. Mnatsakanian In Part I (Forum Geom., 15 (2015)...
Volumes of solids swept tangentially around cylinders - Tom M. Apostol and Mamikon A. Mnatsakanian In earlier work ([1]-[5]) the authors used...
Heronian triangles of class K: congruent incircles cevian perspective - Frank M. Jackson and Stalislav Takhaev We relate the properties of a...
Generalized Tucker circles - Nikolaos Dergiades It is known that if we cut the sides of the angles of a triangle, with six consecutive...
