Update cheatsheet.en.md

01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/02.mirror/02.new-course-overview/cheatsheet.en.md

@@ -148,7 +148,17 @@ side* of the mirror.<br><br>
 
 * with **real objects** 
 
+![](Thin-spherical-mirror-InfAC-1000.jpg)
+Concave mirror with object between infinity and C
 
+![](Thin-spherical-mirror-CAF-1000.jpg)
+Fig. 6.  Concave mirror with object between C and F/F’
+
+![](Thin-spherical-mirror-FAS-1000.jpg)
+Fig. 5.  Concave mirror with object between F/F’ and S
+
+![](Thin-spherical-mirror-InfAS-1000.jpg)
+Fig. 8.  Convex mirror