--- /dev/null
+.. _length_2d_page:
+
+*********
+Length 2D
+*********
+
+This quality control criterion consists of calculation of length of the links between corner nodes of mesh faces.
+
+**To apply the Length 2D quality criterion to your mesh:**
+
+#. Display your mesh in the viewer.
+#. Choose **Controls > Face Controls > Length 2D** or click **"Length 2D"** button in the toolbar.
+
+.. image:: ../images/image34.png
+ :align: center
+
+.. centered::
+ **"Length 2D" button**
+
+Your mesh will be displayed in the viewer with links colored according to the applied mesh quality control criterion:
+
+.. image:: ../images/length2d.png
+ :align: center
+
+
+**See Also** a sample TUI Script of a :ref:`tui_length_2d` operation.
+
+
