Tiling polygons with lattice triangles (Q603872)

In the paper under review, the authors consider the problem of tiling with lattice triangles a simple polygon which is placed in the plane where one vertex is at the origin and an adjacent vertex on the \(x\)-axis. The main result is that the coordinates of the vertices in any tiling of those polygons are rational with some additional restricted conditions. One thing the reviewer wants to remark is that there have been many results on this problem using similar triangles, but in this paper, the authors use lattice triangles.