Tip of triangle rotates at what angle, trigonometrically? (5)
I believe the answer is:
theta
'angle trigonometrically?' is the definition.
I can't judge whether this defines the answer.
'tip of triangle rotates at what' is the wordplay.
'tip of' suggests taking the first letters.
'rotates' shows that the letters should be reversed in order (I've seen 'rotating' mean this).
'what' becomes 'eh' (sound used to ask 'what?' or 'pardon?').
The initial letter of 'triangle' is 't'.
'at'+'eh'='ateh'
'ateh' reversed gives 'heta'.
't'+'heta'='THETA'
Can you help me to learn more?
(Other definitions for theta that I've seen before include "Make amends for" , "Foreign character" , "Greek letter equivalent to th" , "character from Greece" , "letter from Athens" .)