Wow, I thought Gerver once claimed a proof. I'd like to see the analytic expressions for the 15 curved pieces. And maybe the whole area. Too bad it's not π/2 + 2/π (the expected value of a random 3D rotation). --rwg Fred's 3D remark is not just another idle case of Let's add a dimension. Who makes floor-to-ceiling cylindrical furniture? Or does Ikea have a branch in Flatland? Date: 2017-01-04 11:50 From: Brent Meeker <meekerdb@verizon.net> More fun than moving it upstairs. Brent -------- Forwarded Message -------- https://www.math.ucdavis.edu/~romik/movingsofa/ < https://www.math.ucdavis.edu/%7Eromik/movingsofa/> Christine