Two interesting integer parameters of integer-sided triangles - Jose De la Cruz and John F. Goehl When a triangle is described in terms of the...
Orthopoles, flanks, and Vecten points - Todor Zaharinov Erect a square outwardly (or inwardly) from each side of the triangle. For the flank...
The periambic constellation with Altitudes, perpendicular bisectors, and other radical axes in a triangle - Dixon J. Jones Six circles may be...
The Simson triangle and its properties - Todor Zaharinov Let ABC be a triangle and P_1, P_2, P_3 points on its circumscribed circle. The Simson...
Radii of circles in Apollonius' problem - Milorad R. Stevanovic, Predrag B. Petrovic, and Marina M. Stevanovic The paper presents the relation...
Three synthetic proofs of the Butterfly Theorem - Nguyen Tien Dung We give three synthetic proofs of the butterfly theorem, using Thales'...
On centers and central lines of triangles in the elliptic plane - Manfred Evers We determine barycentric coordinates of triangle centers in the...
Orthocenters of simplices on spheres - Kenzi Sato We consider orthocenters of simplices of the unit sphere of the n-dimensional Euclidean space....
On the Feuerbach triangle - Dasari Naga Vijay Krishna We study the relations among the Feuerbach points of a triangle and the feet of the angle...
Another simple construction of the golden section in an isosceles triangle - Tran Quang Hung Given an isosceles triangle, consider the circle...
On the relations between truncated cuboctahedron, truncated icosidodecahedron and metrics - Özcan Gelisgen The theory of convex sets is a vibrant...
A group theoretic interpretation of Poncelet's theorem with the complex case - Albrecht Hess Poncelet's theorem about polygons that are inscribed...
The two incenters of an arbitrary convex quadrilateral - Nikolaos Dergiades and Dimitri M. Christodoulou For an arbitrary convex quadrilateral...
Properties of the tangents to a circle that forms Pascal points on the sides of a convex quadrilateral - David Fraivert The theory of a convex...
Reflections and incidence constraints on the plane - Jorge C. Lucero This article reviews the so-called ``axioms'' of origami (paper folding),...
On the orthogonality of a median and a symmedian - Navneel Singhal We give a synthetic proof of F. J. Garcia Capitan's theorem on the lemniscate...
About a strengthened version of Erdos-Mordell inequality - Dan Stefan Marinescu and Mihai Monea In this paper, we use barycentric coordinates to...
Triangle constructions based on angular coordinates - Thomas D. Maienschein and Michael Q. Rieck Two very different, yet related, triangle...
Projective geometry in relation to the excircles - Prasanna Ramakrishnan In this article, we explore a small collection of results in relation to...
On the Tucker circles - Sandor N. Kiss and Paul Yiu Parametrizing Tucker circles by the lengths of their antiparallel sides, we find conditions...
