Article date: Oct 1973
Article title: "Look-see" diagrams that offer visual proof of complex algebraic formulas
Mathematical Games column? Y
Book: 11. Knotted Doughnuts and Other Mathematical Entertainments
Chapter: 16. Look-See Proofs
This data confirmed? yes
Notes
Peter Rowlett (27 August 2022):
Peter Rowlett initial guess (Uncertain)
Peter Rowlett (1 November 2023):
I have seen this chapter and column side-by-side and they match.