Hi Wendy - If you are working on the sawtooth star, then maybe I can help with your cutting sizes. I'm going to assume that your 4 1/2" measurement is unfinished size since it would be a pretty odd finished size. I think in terms of finished size, so that's what I'll use in my explanation. You should double-check my explanation since it's just 6am here.
For the star block, you have 3 basic units: the center square, the corner squares and the flying geese. If the block finishes at 4", then the center square will be 2"x2" finished, the corner squares will by 1"x1" finished and the flying geese will be 1"x2" finished. The squares are easy, cut 1 1/2"x1 1/2" and 2 1/2" by 2 1/2" squares. For the flying geese, the larger center triangle is cut as a quarter square triangle to get the straight of grain on the outside. Since that straight edge is 2" finished, we add 1 1/4" to the finished size of the square for the seam allowances, giving us a 3 1/4" square cut into quarters for this part of the unit. The two small triangles in this unit are cut as half square triangles, again for straight of grain placement. Add 7/8" for seam allowances and that gives you 1 7/8" squares for these units.
So, the cutting for one sawtooth star block would be:
1 - 2 1/2"x2 1/2" square
4 - 1 1/2"x1 1/2" squares
1 - 3 1/4"x3 1/4" square cut into quarters
4 - 1 7/8"x1 7/8" square cut into halves
These are exact measurements and do not leave any extra for trimming down.
Hope this helps,
Nancy
PS - Wish I could join you guys, but I have to work today. But I'll be watching to see what you do!