Construction of Malfatti squares - Floor van Lamoen and Paul Yiu We give a very simple construction of the Malfatti squares of a triangle, and...
On the Parry reflection point - Cosmin Pohoata We give a synthetic proof of C. F. Parry's theorem that the reflections in the sidelines of a...
A short trigonometric proof of the Steiner-Lehmus theorem - Mowaffaq Hajja We give a short trigonometric proof of the Steiner-Lehmus theorem....
Kronecker theorem and a sequence of triangles - Panagiotis T. Krasopoulos We investigate the dynamic behavior of the sequence of nested triangles...
Angles, area and perimeter caught in a cubic - George Baloglou and Michel Helfgott The main goal of this paper is to establish sharp bounds for...
Two triads of congruent circles from reflections - Quang Tuan Bui Given a triangle, we construct two triads of congruent circles through the...
An affine variant of a Steinhaus problem - Jean-Pierre Ehrmann Given a triangle ABC and three positive real numbers u, v, w, we prove that there...
On a construction of Hagge - Christopher Bradley and Geoff Smith In 1907 Hagge constructed a circle associated with each Cevian point P of...
How pivotal isocubics intersect the circumcircle - Bernard Gibert Given the pivotal isocubic K= pK(Omega,P), we seek its common points with the...
Another verification of Fagnano's theorem - Finbarr Holland We present a trigonometrical proof of Fagnano's theorem which states that, among all...
Cyclic quadrilaterals with prescribed Varignon parallelogram - Michel Bataille We prove that the vertices of a given parallelogram P are the...
The Soddy circles - Nikolaus Dergiades Given three circles externally tangent to each other, we investigate the construction of the two so called...
Constructive solution of a generalization of Steinhaus' problem on partition of a triangle - Jean-Pierre Ehrmann We present a constructive...
Steinhaus' problem on partition of a triangle - Apoloniusz Tyszka H. Steinhaus has asked whether inside each acute triangle there is a point from...
On a product of two points induced by their cevian triangles - Cosmin Pohoata and Paul Yiu The intersections of the corresponding sidelines of...
Fixed points and fixed lines of Ceva collineations - Clark Kimberling In the plane of a triangle ABC, the U-Ceva collineation maps points to...
Some triangle centers associated with the excircles - Tibor Dosa We construct a few new triangle centers associated with the excircles of a...
On the diagonals of a cyclic quadrilateral - Claudi Alsina and Roger B. Nelsen We present visual proofs of two lemmas that reduce the proofs of...
Coincidence of centers for scalene triangles - Sadi Abu-Saymeh and Mowaffaq Hajja A center function is a function Z that assigns to every...
Heronian triangles whose areas are integer multiples of their perimeters - Lubomir Markov We present an improved algorithm for finding all...
