On the intercepts of the OI-line - Lev Emelyanov We prove a new property of the intercepts of the line joining the circumcenter and the incenter...
Triangles with special isotomic conjugate pairs - K. R. S. Sastry We study the condition for the line joining a pair of isotomic conjugates to be...
A simple construction of the congruent isoscelizers point - Eric Danneels We give a very simple construction of the congruent isoscelizers point...
Signed distances and the Erdos-Mordell inequality - Nikolaos Dergiades Using signed distances from the sides of a triangle we prove an inequality...
On the areas of the intouch and extouch triangles - Juan Carlos Salazar We prove an interesting relation among the areas of the triangles whose...
Orthopoles and the Pappus theorem - Atul Dixit and Darij Grinberg If the vertices of a triangle are projected onto a given line, the...
Steiner's theorems on the complete quadrilateral - Jean-Pierre Ehrmann We give a translation of Jacob Steiner's 1828 note on the complete...
The Archimedean circles of Schoch and Woo - Hiroshi Okumura and Masayuki Watanabe We generalize the Archimedean circles in an arbelos...
Extremes areas of triangles in Poncelet's closure theorem - Mirko Radic Among the triangles with the same incircle and circumcircle, we determine...
Another 5-step division of a segment in the golden section - Kurt Hofstetter We give one more 5-step division of a segment into golden section,...
Antiparallels and concurrency of Euler lines - Nikolaos Dergiades and Paul Yiu We study the condition for concurrency of the Euler lines of the...
Antiorthocorrespondents of Circumconics - Bernard Gibert This note is a complement to our previous paper Orthocorrespondence and Pivotal Cubics....
Sawayama and Thebault's theorem - Jean-Louis Ayme We present a purely synthetic proof of Thébault's theorem, known earlier to Y. Sawayama. [IMG]...
Circumrhombi - Floor van Lamoen We consider rhombi circumscribing a given triangle ABC in the sense that one vertex of the rhombus coincides with...
Circumcenters of residual triangles - Eckart Schmidt This paper is an extension of Mario Dalcín's work on isotomic inscribed triangles and their...
A 5-step division of a segment in the golden section - Kurt Hofstetter Using ruler and compass only in five steps, we divide a given segment in...
Two triangle centers associated with the excircles - Milorad Stevanovic The triangle formed by the second intersections of the bisectors of a...
The Apollonius circle and related triangle centers - Milorad Stevanovic We give a simple construction of the Apollonius circle without directly...
A tetrahedral arrangement of triangle centers - Lawrence Evans We present a graphic scheme for indexing 25 collinearities of 17 triangle centers...
The parasix configuration and orthocorrespondence - Bernard Gibert and Floor van Lamoen We introduce the parasix configuration, which consists of...
