Truncated hexagonal tiling
In geometry, the truncated hexagonal tiling is a semiregular tiling of the Euclidean plane. There are 2 dodecagons (12-sides) and one triangle on each vertex.
On painted porcelain, China
In geometry, a dodecagon, or 12-gon, is any twelve-sided polygon.
The Vera Cruz church in Segovia
A 1942 British threepence, reverse
Image: Wooden pattern blocks dodecagon