PAL

Ptolemaeus Arabus et Latinus

_ (the underscore) is the placeholder for exactly one character.
% (the percent sign) is the placeholder for no, one or more than one character.
%% (two percent signs) is the placeholder for no, one or more than one character, but not for blank space (so that a search ends at word boundaries).

At the beginning and at the end, these placeholders are superfluous.

مثلث ‘spherical triangle’

Arabic

References: Alm. MS Leiden: f. 16r
Translation of:
Greek: τρίπλευρον [Alm. Heiberg: II.3, 96:24]
Synonyms:
ذو ثلاثة أضلاع[Alm. MS Tunis: 21a.18]