Specifies the text height for scriptscriptstyle text in Maths, which is used for used for 2nd level sub- & superscripts, roots and 3rd level fractions. The height is given as a percentage of the text height set for displaystyle and textstyle text styles via <?tcusth1>.
Syntax
<?tcusth3 height3:f?> <?tcusth3
[no parameter]
Invoke the tcusth3 dialog box.
height3
The percentage of the <?tcusth1> property value: to one decimal place.