/*!

\page length_2d_page Length 2D

\n This quality control criterion consists of calculation of length of
the links between corner nodes of mesh faces.

<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 > Face Controls > Length 2D</b> or click
<em>"Length 2D"</em> button in the toolbar. 

\image html image34.png
<center><em>"Length 2D" button</em></center>

Your mesh will be displayed in the viewer with links 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.  

*/