After playing with this a bit more -
QuiltnNan says that she came up with a "finished unit" size of 16 x 6. I also came up with that. I haven't figured out how wide to cut the strips yet.
krafty14 suggests that the five narrow strips are pieced and then cut at 45 degree angles and a white triangle is sewn on each end. I think that makes sense.
If the rectanglular unit finishes at 6 x 16, I think the narrow strips are cut at (square root of 2 + 1/2 inch)
The square root of 2 is 1.414 and then add another 0.5 inch - that is 1.914 inches - so if one cuts a "scant" two inch strip, that would come out quite close.
The white strips are triangles that need to finish at 6 inches on their short sides. So - depending on your feelings about grain lines - you could cut squares at 6-7/8 inches and cut them on the diagonal -
Or cut a strip (square root of 72 + 1/2 inch)
8.48 + 0.5 inch = 8.98 inches -> I would cut strips 9 inches wide