I'm doing one right now, and I'm following the 2nd book (the one with cubes) and she says to cut the rows 3 3/4" wide because you avoid getting repeats of the same triangles. Then you cut your triangles using the 3-3/4" line. You could do it with 3-1/2" rows and the 3-1/2" line - your hexagons would be a bit smaller.