You'll need:
Eight 5" squares of background fabric
Four 5" squares of fabric #1 (Zig Zag)
Two 5" squares of fabric #2 (Grey)
Two 5" squares of fabric #3 (Green)

Using the directions from this blog post, use the above fabrics to make 16 half square triangles. Arrange them as seen in this picture.

Sew them together into four rows

And sew the rows together, matching up corners, to get the finished block

Three down, six to go.
Four 5" squares of fabric #1 (Zig Zag)
Two 5" squares of fabric #2 (Grey)
Two 5" squares of fabric #3 (Green)

Using the directions from this blog post, use the above fabrics to make 16 half square triangles. Arrange them as seen in this picture.

Sew them together into four rows

And sew the rows together, matching up corners, to get the finished block

Three down, six to go.