Right-angle shape (3)
I believe the answer is:
ell
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">right-angle shape</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ell that I've seen before include "Former textile measure" , "Old measure of length about 45 inches" , "Embellish with old measure of length" , "distance" , "approximately 45 inches" .)