GeoDom

Los puntos $E$ y $F$ yacen en el lado $BC$ del cuadrilátero convexo $ABCD$ (con $E$ más cerca que $F$ de $B$). Se sabe que $\angle{BAE}=\an...

Proposition $1$ . Let $ABC$ be a short golden triangle $(108°-36°-36°)$. Call $H$ the orthocenter of $\triangle{ABC}$ and let $h_ah_bh_c$ b...

Antes de ir al móvil principal de este artículo, definamos qué es un árbelos. Árbelos es la figura formada por tres semicírculos mutuamente...

In euclidean geometry, the  Fuhrmann triangle and the  Hexyl triangle  (and others) are two special triangles with a plethora of surprisin...

Consider two circles with centers $A$ and $B$. Call $A'$, $A''$ the two intersections of the line $AB$ and the circle centered ...

Let $A$ and $B$ be the centers two circles $(A)$, $(B)$. From $A$, draw a tangent to $(B)$ at $C$. From $B$, draw two tangents to $(A)$ in ...

I guess you are familiar with the result described as follows: If $ABC$ is an equilateral triangle, and $P$ is any point on the i...