Article date: Jul 1964
Article title: Curious properties of a cycloid curve
Mathematical Games column? Y
Book: 6. Martin Gardner's Sixth Book of Mathematical Games from Scientific American
Chapter: 13. The Cycloid: Helen of Geometry
This data confirmed? yes
Notes
Peter Rowlett (27 August 2022):
Peter Rowlett initial guess (Uncertain)
Peter Rowlett (29 October 2023):
I have seen this chapter and column side-by-side and they match.