Patent ID: 7559176

Claim:
An apparatus comprising: an elongated regular octagonal first tubular form element, wherein the tubular form element includes a tubular boundary of seven adjacent wall faces and one open face, wherein the tubular boundary bounds a longitudinal interior chamber, wherein the tubular form element includes six female engagement portions each configured as a T-shaped slot having a locus of connection to engagingly receive a male engagement portion configured as a T-shaped fin also having a locus of connection, wherein each female engagement portion extends into the longitudinal interior chamber from a vertex of adjacent wall faces, wherein each female engagement portion includes an opening at the tubular boundary as the T-shaped slot, wherein, the tubular form element includes two male engagement portions extending outwardly of the tubular boundary, wherein the two male engagement portions at the open face of the first form element and, are adapted to engage with two female engagement portions of a elongated regular octagonal second tubular form element on any one of five adjacent wall faces having two female engagement portions at two vertices of the wall face, wherein, when engaged, the male engagement portions of the first tubular form element and the female engagement portions of the second tubular form element identify a relationship of common loci of each connection with placement of each locus at the vertices of the rectangular octagons of the first tubular form element and the second tubular form element, wherein, when engaged, the female engagement portions extend into the longitudinal interior chamber to permit the internalization of the connection of the male engagement portion of the first tubular form element configured as the T-shaped fin and the female engagement portion of the second tubular form element configured as the T-shaped slot to allow external side surfaces of adjacent tubular form elements as wall faces to lie within a plane for creation of a flat surface arrangement, and wherein the flat surface arrangement is adapted to be created by female engagement portions of adjacent form elements engaging an insert panel at two male engagement portions, also configured as T-shaped fins identical to the male engagement portions on the first tubular form element, to form a substantially flat wall surface.