Angle symbol, in math (5)

I believe the answer is:

theta

(Other definitions for theta that I've seen before include "Greek letter equivalent to th" , "letter from Argos?" , "Greek character" , "Character from overseas" , "letter to Greeks" .)

I've seen this clue in the Universal.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.