A strong triangle inequality in hyperbola geometry - Csaba Biró and Robert C. Powers For a triangle in the hyperbolic plane, let α, β, γ denote...
The golden section in a planar quasi twelve-point star - Hartmut Warm A planar quasi twelve-point star is a configuration formed by selected...
Solutions of two Japanese ellipse problems - J. Marshall Unger Two premodern Japanese theorems involving an ellipse and tangent circles are...
Wernick's list with a final update - Pascal Schreck, Pascal Mathis, Vesna Marinkovic, and Predrag Janicic We present a final status of all...
A ladder ellipse problem - Alan Horwitz We consider a problem similar to the well-known ladder box problem, but where the box is replaced by an...
Archimedes' arbelos to the n-th dimension - Antonio M. Oller-Marcén The arbelos was introduced in Proposition 4 of Archimedes' Book of Lemmas. It...
Isogonal conjugates in a tetrahedron - Jawad Sadek, Magid Bani-Yaghoub and Noah H. Rhee The symmedian point of a tetrahedron is defined and the...
Trisecting an angle correctly up to arcminute - Joseph Tonien We present a simple compass-and-straightedge construction method of approximately...
Geogebra construction of the roots of quadratic, cubic and quartic equations - Nikolaos Dergiades We construct geometrically the roots of a...
[LuyenThiThuKhoa.vn]_Integral right triangle and rhombus pairs with a common area and a common perimeter - Shane Chern We prove that there are...
Two pairs of Archimedean circles derived from a square - Hiroshi Okumura We construct two pairs of Archimedean circles in the square built on the...
On the coincidences of Pascal lines - Jaydeep Chipalkatti We show that ψ has two irreducible components: a five-dimensional component of...
Some remarks on a Sangaku from Chiba - Paris Pamfilos In this article we present solutions of a Sangaku problem and related generalizations...
Some theorems on polygons with one-line spectral proofs - Grégoire Nicollier We use discrete Fourier transforms and convolution products to give...
A simple dynamic localization of the gravitational center of a triangle - Grégoire Nicollier We describe the gravitational center of a triangle...
Transforming tripolar into barycentric coordinates - Albrecht Hess A simple construction is presented to find a point with given tripolar...
Topological treatment of Platonic, Archimedean, and related polyhedra - Tom M. Apostol and Mamikon A. Mnatsakanian Platonic and Archimedean...
A Study of Risala al-Watar wa'l Jaib (The Treatise on the Chord and Sine) - Mohammed K. Azarian Risala al-watar wa'l jaib is one of the three...
Circle incidence theorems - J. Chris Fisher, Eberhard M. Schröder, and Jan Stevens Larry Hoehn discovered a remarkable concurrence theorem about...
Construction of Ajima circles via centers of similitude - Nikolaos Dergiades We use the notion of the centers of similitude of two circles to...
