From 0620b93dc9a221a5986932b0fa94b679c8fab29f Mon Sep 17 00:00:00 2001
From: Claude Meny <claude.meny@irap.omp.eu>
Date: Sun, 6 Oct 2019 12:52:42 +0200
Subject: [PATCH] Update cheatsheet.en.md

---
 .../cheatsheet.en.md                          | 29 ++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/02.plane-refracting-surface-overview/cheatsheet.en.md b/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/02.plane-refracting-surface-overview/cheatsheet.en.md
index a2f43ef5d..8d388c88d 100644
--- a/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/02.plane-refracting-surface-overview/cheatsheet.en.md
+++ b/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/02.plane-refracting-surface-overview/cheatsheet.en.md
@@ -208,9 +208,36 @@ propagation of the light (from the object towards the refracting surface)
 in Figures 3 and 4, and 5 and 6 below, and review NOTE 1.
 !
 
+#### Examples of graphical situations, with analytical results to train
 
+* with real objects
+
+[]()<br>
+Fig. 4.
+
+[]()<br>
+Fig. 5.
+
+[]()<br>
+Fig. 6.
+
+[]()<br>
+Fig. 7.
+
+* with virtual objects
+
+[]()<br>
+Fig. 8.
+
+[]()<br>
+Fig. 9.
+
+[]()<br>
+Fig. 10.
+
+[]()<br>
+Fig. 11.
 
-#### Non stigmatism of spherical refracting surfaces
 
 Ray tracing study of a **spherical refracting surface** :
 [Click here for geogebra animation](https://www.geogebra.org/material/iframe/id/gvkqgrpe)<br>