Chris Maslanka (Guardian newspaper, Saturday October 16th 2010) diagrams the following bilaterally symmetric architectural decoration, comprising a small circle surrounded by a pair of larger arcs tangent to it, the latter centred on a line segment also tangent to it; and asks, given the segment has unit length, what radius has the circle? Fred Lunnon @ @ @ @ * * @ @ * * @ @ * * @ @ * * @ @ * * @ @ * * @ @ * * @ @----------*-*----------@