Martha C.'s block
She modified my pattern by adding seam lines,
thus subtracting Y Seams.
She added seams in the top half.
This is the original pattern with B and C requiring set in seams.
I drew up her pattern in EQ8. The pieces have new letters here.
For the large background triangles A
Cut 3 squares 4-1/4". Cut each in half diagonally to make 2 triangles. You need 6.
For the small background triangles B
Cut 2 squares 3-3/8". Cut each in half diagonally to make 2 triangles. You need 4.
Wait a minute.
You have to do this too.
The largest triangle is now cut in half and is the same size as A.