Let A, B, C represent the vertices of a triangle, where A is the origin and B and C have position b and c respectively.* Points M, N and P are taken on sides AB, BC and CA respectively, such that `(AM)/(AB)=(BN)/(BC)=(CP)/(CA)=alpha` . If `triangle ` represent the area enclosed by the three vectors AN, BP and CM, then the value of `alpha`, for which `triangle` is least