The big turquoise triangle is 3" on the straight sides, in your 9" block. When you re-do for a 12" block, it becomes 4" on straight sides (w/o seam allowance). The little tri is 1.5" on str. sides; in 12" block it becomes 2". The turq. square is also 2" on sides. The beige strips will be 2x4.
This block is tricky because is partly 9-patch and partly 4-patch. The turq. sub-patches in the original are based on 1.5" so when you move to a 12" block, they now are based on 2". (Of course add seam allowance, and the extra bit if you're doing the half-sq triangle 2-at-one-time.)
9 is to 12 as 1.5 is to 2. Draw on graph paper to convince yourself. 
Hope this helps... Nancy
(PM if you want)
Last edited by nanibi; 02-10-2013 at 01:25 PM.