  We show how we found substitution rules for a quasiperiodic tiling with local
rotational symmetry and inflation factor 1 + sqrt(3). The base tiles are a
square, a rhomb with an acute angle of 30 degrees, and equilateral triangles
that are cut in half. These half-triangles follow three different substitution
rules and can be recombined into equilateral triangles in nine different ways
to make minor variations of the tiling. The tiling contains quasiperiodically
repeated 12-fold rosettes. A central rosette can be enlarged to make an
arbitrarily large tiling with 12-fold rotational symmetry. An online computer
program is provided that allows the user to explore the tiling.
