The Mathematical Gazette is the original journal of the Mathematical Association and it is now over a century old. Its readership is a mixture of school teachers, college and university lecturers, ...

https://doi.org/10.4169/amer.math.monthly.124.1.70 https://www.jstor.org/stable/10.4169/amer.math.monthly.124.1.70 We provide a geometric explanation, based on ...