Minecraft wiki entry for Creating_shapes, associated text: A "true" equilateral triangle has sides of 60 degrees, which can be approximated using the "angled lines" char above as a 30-degree angle from the perpendicular or vertical. This could be approximated by doing a 1-block segment every (alternately) two and three 2-block segments, but this may end up looking uneven, and the difference will only be apparent for fairly large triangles. A perfectly equilateral triangle is possible if it is not orthogonal to any of the coordinate axes, but rather orthogonal to the space diagonal of a block.