diff --git a/GraphicsView/demo/Polygon/Polygon_2.cpp b/GraphicsView/demo/Polygon/Polygon_2.cpp
index 517b71b336d..6e49bb23736 100644
--- a/GraphicsView/demo/Polygon/Polygon_2.cpp
+++ b/GraphicsView/demo/Polygon/Polygon_2.cpp
@@ -415,6 +415,8 @@ MainWindow::on_actionMaximumAreaKGon_triggered()
   
     kgongi->modelChanged();
     kgongi->show();
+  } else {
+    std::cout << "The polygon must be convex" << std::endl;
   }
 }
 
diff --git a/GraphicsView/demo/Polygon/Polygon_2.ui b/GraphicsView/demo/Polygon/Polygon_2.ui
index aa22e17b0ee..fdb11bb98d2 100644
--- a/GraphicsView/demo/Polygon/Polygon_2.ui
+++ b/GraphicsView/demo/Polygon/Polygon_2.ui
@@ -231,7 +231,7 @@
   </action>
   <action name="actionMaximumAreaKGon">
    <property name="text">
-    <string>Maximum Area K-gon</string>
+    <string>Maximum Area Triangle</string>
    </property>
   </action>
  </widget>