diff --git a/data/part-5/1-learning-object-oriented-programming.md b/data/part-5/1-learning-object-oriented-programming.md
index 17548639..0e727c89 100644
--- a/data/part-5/1-learning-object-oriented-programming.md
+++ b/data/part-5/1-learning-object-oriented-programming.md
@@ -715,7 +715,7 @@ System.out.println(first.surfaceArea());
 (40, 80)
 (10, 10)
 (39, 80)
-3920
+3120
 
 </sample-output>