Overlapping Octadecagons_1

Folded from a hexagonal piece of paper.

The circles in this model are actually octadecagons, that is, polygons with 18 sides.

If the side length of the hexagon we start with is 1,

then the side length of the completed model is 1-2sin(20°)/tan(80°)≈0.879,

and so the efficiency of this tessellation is as high as (1-2sin(20°)/tan(80°))²≈0.773.

The configuration of octadecagons is the same as that of Eric Gjerde's Spread Hexagons.

Close-up view is here.

Done