Click on the Small Triangles button
to display its dialog box, which you can use to highlight and delete small triangles.
You use the Height (less than) box to specify the triangles that you want to select. The height of a triangle is the distance between the longest side and the third node.
The Number of Triangles box displays the number of triangles which are considered small, when this has been calculated. This box displays not computed if you have not yet calculated the number of small triangles.
Click on the Highlight button to display the number of small triangles in the Number of Triangles box, and to highlight them in red in the Graphics window.
Click on the Delete button to delete all the small triangles, as defined by the specified height.