To avoid all those bias edges inherent in the method you described, please try this quick way of sewing the HSTs. Cut your original squares at least 1" larger (more if you are less confident in your seam allowance) than the finished HST you want.

Jan in VA

I believe what you want to do is multiply the size of half triangle square you want by 1.41, then add .5 to that figure to allow for the seam allowances. So, 2.75 times 1.41 equals 3.88. Add .5 which gives you 4.38. I would round up to 4.5. Give that a try....hopefully that helps?

For future reference...Kaye England has created Quarter Square and Half Square Triangle rulers that I really like. Her math is easy to calculate to get the size triangle you want. The triangles are cut from strips of fabric.

Her line of rulers are called "Nifty Notions". The colors on her rulers are pink for 1/4" and green for 1/2". I find these easier to read than the all yellow ones.

For cutting the strips DH and I like the Tru Cut ruler and companion rotary cutter made by the Grace company for more accurate strips. Happy Sewing!

That's how I do it too. I saw it on Lynn Wilder's website. If you want to make 8 finished 2 3/4" HST, add 1" to the 2 3/4" and multiply by 2... So you would start with a 7 1/2" square. Jan, what software did you use to draw that nice diagram?

i failed to say that you would start with two 7 1/2" squares 😊.

If you are working with bias cuts I should starch well before sewing. When the quilt is finished a wash will remove all the starch. The bias edges will stretch and move if you aren't not careful.

Thank you for that correction, Maureen! I KNEW as I posted it I was wrong, but the impression wasn't strong enough to make me double check myself today -- I was too sleepy! I hope she catches it before she uses my my directions, if she so chooses.

I use the very simple Paint which comes with the Windows 10 (and earlier) operating systems. It works well for me, I'm finally familiar enough with it, and I didn't have to buy anything else to get done what I wish to do.

Jan in VA

Thanks Jan!

That formula is for quarter square triangles. To get half square triangles you add 7/8" to the finished size.
Sharon in Texas

Hello:
In Jennie's video she started with a layer cake, 10 inch square. Cut that into 4ths which would be 5 inch squares. She used the 5 inch squares for the HST and then trimmed to size. Go ahead and try this method as a learning process. The HST are small and the bias may not present a problem. Starch will help. While bias stretches it also eases nicely.
If you require 8 HST of the same color Jan in VA has a good method and it gives straight edges. Still plan on trimming.