In this party season, a little storm of confetti (or maybe snow, for those in the northern hemisphere)…

Each parallelogram is in a 3 x 2 unit, which is offset from the next unit by a 2 x 1 rectangle. The parallelograms could be constructed by flanking a 3 x 2 rectangle with two 3 x 1 triangles (paper-piecing for accuracy, perhaps). Or, pair two 3:1 half-rectangle triangles back to back, which introduces new colour/fabric possibilities to the design:

The good news is, Bloc Loc makes a 3:1 half-rectangle triangle ruler – in two sizes!

 

(Not an affiliate link… I just love the precision that Bloc Locs enable!)