A synthetic proof of Goormaghtigh's generalization of Musselman's theorem - Khoa Lu Nguyen We give a synthetic proof of a generalization by...
Where are the conjugates - Steve Sigur The positions and properties of a point in relation to its isogonal and isotomic conjugates are...
A generalization of the Kiepert hyperbola - Darij Grinberg and Alex Myakishev Consider an arbitrary point P in the plane of triangle ABC with...
The twin circles of Archimedes in a skewed arbelos - Hiroshi Okumura and Masayuki Watanabe Any area surrounded by three mutually touching circles...
A projective generalization of the Droz-Farny line theorem - Jean-Pierre Ehrmann and Floor van Lamoen LTTK TEZ xin giới thiệu với bạn đọc yêu...
A purely synthetic proof of the Droz-Farny line theorem - Jean-Louis Ayme We present a purely synthetic proof of the theorem on the Droz-Farny...
On the existence of triangles with given lengths of one side and two adjacent angle bisectors - Victor Oxman We give a necessary and sufficient...
Inscribed squares - Floor van Lamoen We give simple constructions of various squares inscribed in a triangle, and some relations among these...
Further inequalities of Erdos-Mordell type - Walther Janous We extend the recent generalization of the famous Erdos-Mordell inequality by Dar and...
Another proof of Fagnano's inequality - Nguyen Minh Ha LTTK TEZ xin giới thiệu với bạn đọc yêu thích tạp chí Hình học Geometricorum một bài viết...
Generalized Mandart conics - Bernard Gibert We consider interesting conics associated with the configuration of three points on the...
On some actions of D_3 on the triangle - Paris Pamfilos The action of the dihedral group D_3 on the equilateral triangle is generalized to...
Garfunkel's inequality - Minh Ha Nguyen and Nikolaos Dergiades Let I be the incenter of triangle ABC and U, V, W the intersections of the...
A grand tour of pedals of conics - Roger C. Alperin We describe the pedal curves of conics and some of their relations to origami folding axioms....
A theorem on orthology centers - Eric Danneels and Nikolaos Dergiades We prove that if two triangles are orthologic, their orthology centers have...
The intouch triangle and the OI-line - Eric Danneels We prove some interesting results relating the intouch triangle and the OI line of a...
Three pairs of congruent circles in a circle - Li C. Tien Consider a closed chain of three pairs of congruent circles of radii a, b, c. The...
Minimal chords in angular regions - Nicolae Anghel We use synthetic geometry to show that in an angular region minimal chords having a prescribed...
The vertex-midpoint-centroid triangles - Zvonko Cerin This paper explores six triangles that have a vertex, a midpoint of a side, and the...
On the Schiffler point - Charles Thas Suppose that ABC is a triangle in the Euclidean plane and I its incenter. Then the Euler lines of ABC, IBC,...
