diff --git a/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/05.classical-mechanics/vector-analysis/cheatsheet.fr.md b/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/05.classical-mechanics/vector-analysis/cheatsheet.fr.md
index 06d28f8b7..2bc361603 100644
--- a/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/05.classical-mechanics/vector-analysis/cheatsheet.fr.md
+++ b/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/05.classical-mechanics/vector-analysis/cheatsheet.fr.md
@@ -89,9 +89,31 @@ tri-lingual use.
 ![](space-orientation-law-1_L1490.png)
 
 
-cylindrical_coordinates.png
+##### Sistemas de coordenada / systèmes de coordonnées / coordinate systems
+
+*[ToDoAgain]*
+
+![](cartesian_coordinates.png)
+
+[ES] ¿Homogeneizar con la misma definición para el ángulo en coordenadas cilíndricas y esférica?<br>
+[FR] Homogénéiser avec la même définition pour l'angle en coordonnées cylindriques et sphériques?<br>
+[EN] Homogenize with the same definition for the angle in cylindrical and spherical coordinates?
+
+*[ToDoAgain]*
+
+![](cylindrical_coordinates.png)
+
+*[ToDoAgain]*
+
+![](sspherical_coordinates.png)
+
+
+
+
+
+
+
 
-spherical_coordinates.png