diff --git a/lectures/21_trees_IV/README.md b/lectures/21_trees_IV/README.md
index f0eaecb..d82f866 100644
--- a/lectures/21_trees_IV/README.md
+++ b/lectures/21_trees_IV/README.md
@@ -82,5 +82,6 @@ class Node {
     Node* right;
   };
 ```
+![alt text](Trinary_trees.png "Trinary Trees example")