  A tiling is a decomposition of a polygon into finitely many non-overlapping
triangles. We prove that if a regular n-gon, $n \geq 5$, $n \neq 28$, can be
tiled with similar right triangles, then one of the angles of these triangles
is in $\left\{\frac{\pi}{n},\frac{2\pi}{n}, \frac{\pi}
{6}+\frac{2\pi}{3n}\right\}$. Some related results were previously obtained by
M.Laczkovich and B. Szegedy.
