A fluid-filled structure, such as a bladder, is disclosed. The bladder has
a first surface and an opposite second surface that are peripherally
joined to define various edges. The bladder encloses a fluid between the
first surface and the second surface. A portion of the edges may have a
concave configuration, or the edges may have both concave and convex
configurations. A shape of the bladder may be a tessellation pattern so
that a plurality of the bladder may be efficiently.