A hanger for supporting a held member from a holding member is provided with a seat member adapted for supporting the held member, first and second side members connected to the seat member, the first and second side members having lower portions and upper portions, the lower portions of the first and second side members each having inner an face and an outer face with the inner faces facing each other, and the upper portions of the first and second side members being connected to first and second back flanges respectively, the upper portions of the first and second side members each having an inner face and an outer face, and the first and second back flanges being adapted to be connected to the holding member by a plurality of fasteners, wherein the inner faces of the lower portions of the first and second side members and the inner faces of the upper portions of the first and second side members form reflex angles with each other.