It is possible to piece this using only square and half-square triangles.
There are a lot of unnecessary seams.
First I'll join the nine blocks in the center to form a large Nine Patch. Then I'll form strips from the other blocks and use them as if I were making a large Log Cabin.
This makes it easy to keep track of what I'm doing and to match seams.
For more piecing go to My Posts by Subject in the sidebar on the right and click on Piecing.