--- /dev/null
+.. _split_biquad_to_linear_page:
+
+******************************
+Split bi-quadratic into linear
+******************************
+
+This functionality allows to split bi-quadratic elements into
+linear ones without creation of additional nodes.
+
+So that
+
+* bi-quadratic triangle will be split into 3 linear quadrangles;
+* bi-quadratic quadrangle will be split into 4 linear quadrangles;
+* tri-quadratic hexahedron will be split into 8 linear hexahedra;
+* quadratic segments adjacent to the split bi-quadratic element will be split into 2 liner segments.
+
+.. image:: ../images/split_biquad_to_linear_mesh.png
+ :align: center
+
+.. centered::
+ "Mesh before and after splitting"
+
+**To split bi-quadratic elements into linear:**
+
+#. From the **Modification** menu choose the **Split bi-quadratic into linear** item or click **"Split bi-quadratic into linear"** button in the toolbar.
+
+ .. image:: ../images/split_biquad_to_linear_icon.png
+ :align: center
+
+ .. centered::
+ **"Split bi-quadratic into linear" button**
+
+ The following dialog box shall appear:
+
+ .. image:: ../images/split_biquad_to_linear_dlg.png
+ :align: center
+
+
+#. Select a mesh, groups or sub-meshes in the Object Browser or in the Viewer.
+#. Click the **Apply** or **Apply and Close** button.
+
+**See Also** a sample TUI Script of a :ref:`tui_split_biquad` operation.
+
+
