Generalized Archimedean arbelos twins - Nikolaos Dergiades We generalize the well known Archimedean arbelos twins by extending the notion of...
Some circles associated with the Feuerbach points - Nguyen Thanh Dung Consider a triangle with its nine-point circle tangent to the incircle and...
Congruent contiguous excircles - Mihaly Bencze and Ovidiu T. Pop In this paper we present some interesting lines in a triangle and we give some...
On a circle containing the incenters of tangential quadrilaterals - Albrecht Hess When we fix one side and draw different tangential...
The diagonal point triangle revisited - Martin Josefsson We derive a formula for the area of the diagonal point triangle belonging to a...
Optimal packings of two ellipses in a square - Thierry Gensane and Pascal Honvault For each real number E in ]0,1], we describe the densest...
Archimedean circles related to the Schoch line - Hiroshi Okumura We give several Archimedean circles of the arbelos related to the Schoch line....
On two triads of triangles associated with the perpendicular bisectors of the sides of a triangle - Shao-Cheng Liu We discover some properties of...
A gallery of conics by five elements - Paris Pamfilos This paper is a review on conics defined by five elements, i.e., either lines to which the...
The triangle of reflections - Jesus Torres This paper presents some results in triangle geometry discovered with the aids of a dynamic software,...
A purely synthetic proof of Dao's theorem on six circumcenters associated with a cyclic hexagon - Telv Cohl We present a purely synthetic proof...
Three constructions of Archimedean circles in an arbelos - Paul Yiu We give ruler and compass constructions of three Archimedean circles in an...
A special point in the arbelos leading to a pair of Archimedean circles - Floor van Lamoen In 2011 Quang Tuan Bui found a beautiful and simple...
Two more pairs of Archimedean circles in the arbelos - Tran Quang Hung We construct two more pairs of Archimedean circles in the arbelos. One of...
Two tangent circles from jigsawing quadrangle - Tran Quang Hung We establish the tangency of two circles associated with the jigsawing quadrangle...
Dao's theorem on six circumcenters associated with a cyclic hexagon - Nikolaos Dergiades We reformulate and give an elegant proof of a wonderful...
A note on Haga's theorems in paper folding - Hiroshi Okumura Haga's three theorems in the mathematics of square paper folding are unified in a...
A simple property of isosceles triangles with applications - Surajit Dutta In this paper we prove a simple property of isosceles triangles and...
Quasi-circumcenters and a generalization of the quasi-Euler line to a hexagon - Michael de Villiers This short note first proves an elementary...
Symbolic substitution has a geometric meaning - Manfred Evers By comparing two different metrics in the affine plane, it is shown that symbolic...
