That's okay. That's what makes the circle of the skirt. If you watch the first video I posted, I think it will answer your questions. Could you give us a link to the pattern you are using? Or at least the name and designer of the pattern?

Edited to add: My first experience with a 10 degree ruler was the Spicy Spiral Table Runner. Making that pattern, you start with a longer cut, then move down the ruler to the next measurement and cut a shorter wedge, continuing until you get to the end of stripset. Then you turn what's left of the stripset and continue cutting shorter and shorter pieces. After sewing all these back together, you trim off the edges and bind. It was a great learning experience about how to use these fun, wedge rulers.

9 X 2.5=22.5 After subtracting 4" for 8 seams if you sewed 9 strips together, you have 18 1/2", so you don't have enough to place the ruler on the 22 mark - that takes 19". Confusing! Can you add another strip?

I have a few times, but I only have one pic of the project to show. It is a spicy spiral. For a tree skirt, I am pretty sure you would want to press your seams open to help with the bulk and bulging in the middle. I know sometimes it is even best to use a 1/8th inch seam allowance if piecing narrow strips.

I used clear medical tape on the back of my ruler to keep it from slipping. It is removable if you wish too.

Remember you have a open space for the tree trunk. That accounts for the extra length you need, right?

Or, use a 1/8" seam allowance. Some patterns call for it with this type of piecing.

Thank you so much! I watched the video and got it! I have half the wedges cut and it looks great.

I have made a couple of things using it. If you are making a circle accurate sewing is a must. It must be exactly 1/4 inch seams or it won't lay flat. If you are off even a little bit that is multiplied 40 times and adds up

I love this quilt. I have never seen it made with a print. Love the borders, also.

THank you for the help.

I just purchased a 9 degree ruler. I want to make a Christmas tree skirt. I look forward to watching the tutorials you've shared. Thank you so much!