Question

Thought of an interesting question while at someone's home about 8 chairs.

Answer 1

Do the chairs have a shape? Answers have been treating the chairs as points, but you can't put the centers of two chairs a foot apart, they wouldn't fit.

If the chairs are circles, then it may not make a difference. But treating chairs as squares certainly would.

Answer 2

I can solve it in two dimensions for n = 2 or n = 3. The answer is 1 foot.

Additional dimensions and numbers larger than 3 I'll leave as an exercise for the reader.