[![enter image description here]]

The figure shows a hexagon and triangle tiled by six tiles, which are pairwise congruent.

My question is:

What is the *smallest* number of polygonal tiles that will tile both a regular hexagon and an equilateral triangle in such a way that all the edges of the tiles are parallel to an edge of the tiled figure?

Small print:

- I define a polygonal tile as a figure comprised of:

A finite set $P$ of at least three points.

The (straight) lines $X\pi(X)$ for each point $X\in P$ and some cyclic permutation $\pi$ of $P$ such that distinct lines do not intersect except at mutual end points.

The region contained by the lines.

- The hexagon, triangle and tiles are assumed to include the vertices, edges and interior.

- The figures tiled must be the union of exactly one congruent copy of each tile (though the set of tiles itself is allowed to contain congruent figures). No copy of a tile can share an interior point with the copy of any other tile, but may share boundary points with one or more.

- A congruent copy of a tile may be a "flipped" version (e.g. the cyan tiles in the above digram are actually mirror images - this is allowed).

: https://i.stack.imgur.com/fxjW6.png