Problem of the Week 1151
Construct a Regular 7-Gon
You have seven one-foot long pieces of pipe and a supply of right-angle connectors. Show how to arrange the seven pieces into a closed path in 3-space, with a right angle between each piece.
It is easy to do this with four pieces, but impossible with three or five pieces.
A full solution is a list of seven points in space making the required right angles.
Source: Problem of the month #97 (Sept. 2010) at http://mathcentral.uregina.ca/mp/previous2010/
© Copyright 2012 Stan Wagon. Reproduced with permission.