Note that these triangles are not equilateral (which, frankly, should have been listed in the product description). Therefore, they are unsuitable for making a mirror mosaic that needs to tesselate isotropically.Mirrors are roughly isoceles. For example, these are the side lengths taken from one such triangle: 27.33 mm, 27.42 mm, 24.65 mm.Mirrors are of okay quality, although edges can have small defects.