GeoDom

Consider a triangle $\triangle{ABC}$, its Incircle, $\psi$, and its $B$-mixtilinear incircle, $\omega$. Let $T$ be the point of tangency of...

Consider a semicircle $(AB)$ and a circle, $w$, tangent internally at $T$. Let $N$ be the point of tangency of $w$ and the diameter, $AB$. ...

Let $ABC$ be a triangle, $P$ a point, $A'B'C'$ the antipedal triangle of $P$ and $A''$, $B''$, $C''$ th...

Two triangles $A_1B_1C_1$ and $A_2B_2C_2$ are Cyclologic if the circles $(A_1B_2C_2)$, $(B_1A_2C_2)$, and $(C_1A_2B_2)$ are concurrent in a...

(Este debate fue radiado originalmente en 1948 en el Tercer Programa de la BBC. Fue publicado en Humanitas en el otoño de 1948) COPLESTON...

Let $ABC$ be any triangle and $I$ its Incenter. Call $E$ and $F$ the reflections of $I$ around the sides $AB$, $BC$, respectively. Now, den...

Let $ABC$ be any triangle and $I$ its Incenter. Call $E$ and $F$ the reflections of $I$ around the sides $AB$, $BC$, respectively. Now, d...