A convex polygon of sides ℓ1,ℓ2,...,ℓn is called ordered if for all reordering (σ(1),σ(2),...,σ(n)) of the set (1,2,...,n) there exists a point P inside the polygon such that dσ(1)<σ(2)<...<dσ(n) , where di represents the distance between P and side ℓi. Find all the convex ordered polygons.
geometrycombinatoricschilean NMO