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+/*!
+
+\page length_2d_page Length 2D
+
+\n This quality control criterion consists of calculation of length of
+the edges combining the meshing elements (triangles and quadrangles)
+of your mesh.
+
+<em>To apply the Length 2D quality criterion to your mesh:</em>
+<ol>
+<li>Display your mesh in the viewer. </li>
+
+<li>Choose <b>Controls > Length 2D</b> or click <em>"Length 2D"</em>
+button in the toolbar.
+
+\image html image34.gif
+<center><em>"Length 2D" button</em></center>
+
+Your mesh will be displayed in the viewer with its elements colored according to the applied mesh quality control criterion:
+
+\image html length2d.png
+</li>
+</ol>
+
+<br><b>See Also</b> a sample TUI Script of a
+\ref tui_length_2d "Length 2D quality control" operation.
+
+*/
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