+<p>For example, hexahedron is analysed via 6 tetrahedrons this way:</p>\r
+\r
+<p><img src="image139.gif" border="0" class="img_whs10"> </p>\r
+\r
+<p> </p>\r
+\r
+<p>For 3D elements with quadrangular faces, aspect ratio of such faces\r
+is also analysed and the maximal one over 3D and 2D qualities is taken.</p>\r
+\r
+<p> </p>\r
+\r