The double reflection -green- of a small arbitrary triangle -center red- [La double réflexion -verte- d'un petit triangle quelconque -rouge au centre-].
See some related bidimensionnal visualizations (possibly including this one), the blue spheres (if any) displaying the intersection points of the blue lines with the red sides:
See some related tridimensionnal visualizations (possibly including this one), the blue spheres (if any) displaying the intersection points of the blue lines with the red faces:
(CMAP28 WWW site: this page was created on 08/07/2016 and last updated on 10/05/2016
08:26:34 -CEST-)