##
Ken's Puzzle of the Week

Circle in a Cube

What is the largest circle you can construct in a unit cube?

Source: Based upon the
IBM Ponder This puzzle for May 2007.

Solutions were received from Earl Gose, Kevin Haborak, Joseph
DeVincentisRadu Ionescu, Dan Dima, K Sengupta. Most determined the
largest circle to be the one inscribed in the hexagon created by joining the
midpoints of the sides of the cube across all six faces (hexagon side length
sqrt(2)/2). The inscribed circle has a diameter of sqrt(3/2).

Mail to Ken