Circle chains inscribed in symmetrical lenses and integer sequences - Giovanni Lucca We derive the conditions for inscribing, inside a...
A generalization of Droz-Farny's line theorem with orthologic triangles - Ngo Quang Duong and Vu Thanh Tung We prove a generalization of...
How to compute a triangle with prescribed lengths of its internal angle bisectors - Gerhard Heindl In 1994 P. Mironescu and L. Panaitopol...
On the existence of a triangle with prescribed bisector lengths - Sergey F. Osinkin We suggest a geometric visualization of the process of...
Minimal proof of a generalized Droz-Farny theorem - Grégoire Nicollier We give a simple proof of a recent generalization of the Droz-Farny line...
A group theoretic interpretation of Poncelet's theorem - Albrecht Hess, Daniel Perrin, and Mehdi Trense Poncelet's theorem about polygons that...
Distances among the Feuerbach points - Sándor N. Kiss We find simple formulas for the distances from the Feuerbach points of a triangle to the...
Euler line in the golden rectangle - Tran Quang Hung We establish a relationship between a golden rectangle and the Euler line of a triangle...
On a new generalization of the Droz-Farny line - Cyril Letrouit We prove a new generalization of the Droz-Farny line theorem, which is based on...
Some monotonicity results related to the Fermat point of a triangle - Toufik Mansour and Mark Shattuck In this paper, we establish a Fermat point...
Two six-circle theorems for cyclic pentagons - Grégoire Nicollier Miquel's pentagram theorem is true for any pentagon. We consider the pentagram...
Another synthetic proof of the butterfly theorem using the midline in triangle - Tran Quang Hung We give a new synthetic proof of the butterfly...
The 19 congruent Jacobi triangles - Glenn T. Vickers With a given triangle and three angles, Jacobi's theorem involves the construction of a new...
A proof of the butterfly theorem using the similarity factor of the two wings - Martin Celli We give a new proof of the butterfly theorem, based...
A characterization of the rhombus - Paris Pamfilos In this article we discuss a simple characterization of the rhombus by considering the...
Apollonian circumcircles of IFS fractals - Jozsef Vass Euclidean triangles and IFS fractals seem to be disparate geometrical concepts, unless we...
A strengthened version of the Erdos-Mordell inequality - Dao Thanh Oai, Nguyen Tien Dung and Pham Ngoc Mai We present a strengthened version of...
Similarities on a sphere - Pascal Honvault We define dilations and similarities on a sphere with the use of quaternions. As an application, we...
The Feuerbach point and the Fuhrmann triangle - Nguyen Thanh Dung We establish a few results on circles through the Feuerbach point of a...
Euclidean figures and solids without incircles or inspheres - Dimitris M. Christodoulou All classical convex planar Euclidean figures that...
