TranslationTransform
[v]TransformationFunction
that translates points by vector v.t = TranslationTransform[{x0, y0}]
t[{x, y}]
From Creating a Sierpinsky gasket with the missing triangles filled in:
Show[Graphics[Table[Polygon[TranslationTransform[{Sqrt[3] (i - j/2), 3 j/2}] /@ {{Sqrt[3]/2, -1/2}, {0, 1}, {-Sqrt[3]/2, -1/2}}], {i, 7}, {j, i}]]]