Possible Clues:

• Three-sided
• Artfully do a girl a turn in a three-sided relationship
• Three sided
• Stated aim by 'Bony', in formation of three lines
• Like warning signs Alan Turing devised, changing number for radius
• Gran joins ritual dancing involving three people?
• Deciphering unfinished Alan Turing rule initially concerning the numbers 0, 1, 3, 6, 10...
• What the long answers all are, more or less
• It's a base in Egypt for a m¿nage ¿ trois
• Like jibs