Dr Aaron J Cotnoir. who is a senior lecturer in the Department of Philosophy at the University of St Andrews, Scotland and part of the Arché Philosophical Research Centre, examines such things in his essay ‘How to make donuts and cut things in half ‘ which can be read in its entirety here.
Pointing out – en passant – that :
“As usual, there are no perfect solutions in philosophy, but there are many good ones. And not all good solutions are equally good.”
BONUS: Dr Cotnoir has also investigated whether a God could create a stone so heavy that he/she/it would be unable to lift it and the question of How Many Angels Can be in the Same Place at the Same Time
The illustration shows (one way) to cut a ring-donut (approximately) in half – creating only one boundary with no holes rather than two.
Research research by Martin Gardiner