Playing around with long X’s – which have the same angle as a 2:1 half-rectangle triangle – produced this sketch, which (again!) lends itself to reverse colour play.

I often copy sketches – sometimes over and over again – to add shading or modify them slightly. Shading this one shows how the individual units repeat: either white on black, or black on white.

This design could be made using ‘triangle in a square’ units, plus long rectangles. You could also paper-piece those X blocks for accuracy.