A composite wall structure for use in a building, such as a geodesic dome, or the outer hull of a pressurized vehicle, such as an airship or submarine, is formed by interconnecting a plurality of three dimensional triangular shaped cells into a shape of desired contour, such as planar or curved, with each individual cell having a sealed chamber that is pressurized, and securing a fluid impervious closure skin to the connected array of cells. Each cell is formed by connecting planar rectangular sidewalls into a triangular frame having opposite sides and attaching a planar triangular panel to each side of the frame in a manner to form a pressure sealed chamber. The hull structure of predetermined shape is capable of captivating a volume of air and/or resisting buckling or failure resulting from fluid pressure on the hull during operation in air or water environments.