Abstract: A support base for a vertical section, wherein the base comprises an upper surface, a lower surface and a perimeter edge. The upper surface has at least two slots into each of which is inserted a lower edge of the vertical section, thereby maintaining the vertical section in an upright position. Multiple support bases are used in combination with multiple vertical sections to assemble a geometric structure that is placed upon a substantially flat surface, and is typically utilized as an animal enclosure, which is particularly effective as a dog enclosure.