diff --git a/forme normale disjonctive.md b/forme normale disjonctive.md
index 7de40507..869b2767 100644
--- a/forme normale disjonctive.md	
+++ b/forme normale disjonctive.md	
@@ -20,3 +20,5 @@ field-groups: [downs]
 depth: [0, 0]
 ```
 
+
+$\displaystyle D = \sqrt{ \left( \frac{l}{2} + r \cos \theta \right)^{2} + \left( \frac{L}{2} + r \sin \theta \right)^{2} }$
\ No newline at end of file