I am new here. Just joined today. Hope I am doing this correctly.

I want to take some 2-1/2 inch strips and cut them into 5-1/2 inch rectangles. Then I want to make a square to cut in half for 2 triangles to go on the short end and then make a square to cut into 2 triangles for the wide edge. How do I figure out what size square to make and then cut into the triangles?

Hi, Diane- welcome to the neighborhood! My reference book says for finished size 2 1/2" to cut the square 3 3/8" then into HST. For 5 1/2" finished size, cut the square 6 3/8". But try those out first with scraps! I don't know the formula for figuring that out- it's been wa-a-ay too many years since geometry! There's a great book called "All-in-one Quilter's Reference Tool" by Harriet Hargrave et al. It has charts of all kinds of measurements. Let me know if those numbers worked for you.

Thank you Carol. I have printed this off and will most definitely try it. I am working on a queen sized quilt right now for a customer to give to his wife for her birthday so it may be a while before I actually get to try it out. But once I get all my rows and sashing sewn together, I just might take a break and try this out too. I found a pattern where they took rectangles and put the triangles all the way around and made the squares and I thought why not try it on some jelly roll strips cut into rectangles. The pattern had a template and odd sized rectangle. I really appreciate the help and so glad to be a part of this group.

I want to take some 2-1/2 inch strips and cut them into 5-1/2 inch rectangles. Then I want to make a square to cut in half for 2 triangles to go on the short end and then make a square to cut into 2 triangles for the wide edge.

Are you wanting HST's (half square triangles) for the sides. A 2 1/2 x 5 1/2" piece will be 2 x 5" when it is sewn in the quilt. For a HST that finishes at 2" you would cut a square 2 7/8" and for a HST that finishes at 5" you would cut your square 5 7/8"

I would cut mine the same as Jacy. I think the measurements Carol gave are more for 1/4 square triangle blocks. To make HSTs you add 7/8" to the finished size of your square.

The measurements I gave were just wrong. They were for 2 1/2" and 5 1/2" finished size. I can't believe I actually even typed "finished" in my reply! Well, I should believe it- It's written right there! Sorry for giving wrong info.

No, I am not wanting half square triangles. I am just wanting to make a square and cut it in half diagonally and have 2 triangles to put on the short ends, the 2-1/2 inch end and then make a square and cut it in half and be able to sew it to the 5-1/2 inch side and then I will have a square and it will look like a rectangle inside a square.

When I think of half square triangles, I think of two fabrics that are cut the same size into a square, sewn across diagonally, cut in two and I have 2 half square triangles.

The name of the quilt pattern that I want mine to look like is called "Scrappy Crossings" but I want to use my Jelly Roll instead of cutting fabric the size the the template they give.

OK, I think I know now what you are wanting, a block like this

To cut a square in half it is an odd measurement. You can cut a 6 1/4" square and a 3 1/4" square and cut them into 1/4 square triangles which will look like this

This gives you a 5 1/2" block, 5" when it is finished.

Thanks so much, Jacy. That is exactly what I am looking for. I tried to reply from my email at yahoo but don't think it went through. Not sure. I really appreciate this and sorry it took me so long to describe what I really needed.