The latest Numberphile video with James Grime discusses "squared squares".
And there is additional footage here.
Also wanted to share a bit more about this photo, which appears in the video and was used with thanks to Iain Strachan.
It shows the Trinity Mathematical Society in 1938, and the key people in the picture for the "squaring square" video are Brooks, Stone, Smith and Tutte.
Mr Strachan came across the picture via his late uncle, Frederick C. Strachan, who is also shown.
Mr Strachan shared the following family story about his uncle.
"He was a very bright mathematician - according to his school (Taunton School), the best the school ever had. He had a free place at Trinity. My Dad, Norman Mervyn Strachan, also got a place at Trinity to read maths, but not a free place. Unfortunately, his parents didn't have enough money to send him, plus the war was coming soon, so Dad joined the Home Guard, and eventually became a Captain in the Royal Corps of Signals.
"Freddie also became an officer in the Royal Corps of Signals (1st Lieutenant). A favourite story in the family was when he was interviewed by a Colonel, initially for the Royal Artillery. The Colonel looked at his application and said 'Hmm I see you have a double First Class Honours degree in mathematics from Cambridge'. 'Yes' says Freddie. The Colonel replies '... I suppose that would include trigonometry?'
"That story got repeated at Freddie's funeral (he died at the age of 94).
"I am somewhat surprised Freddie didn't get recruited by the GCCS to Bletchley Park, like Tutte - he was also a whizz at crosswords. But he graduated in 1938 and got a job as a patent examiner before the war started, and continued in that career afterwards."