Oh I wish I had learned quilting before geometry! Help needed.
 

I had no idea that quilting would bring me to so many story problems in a math class.
i want to make HST that measure 2 3/4 inches. I want to use the method of sewing all around 2 squares and cutting through the center to get 4 HST.

how big do the squares need to be?

the back story is that I want to try my hero, Jenny of Missouri quilts, hunters star quilt, and her lovely video does not spell this out, and I am a nervous nelly beginner. By trial and error I have created 8 too small HST, oops, and 4 much too large, salvageable, but wasteful.
https://m.youtube.com/watch?v=Y7KtiLK_xJk
( now in my 50's I would like to go sit in on middle school math classes. I find that I would now very much like to know some theorems!)

Here's a link to charts and formulas. Scroll down a bit to get to the 4 ata time version. YOu will probably have to make them a bit bigger & cut down. Not sure if 2 3/4 is the raw or finished size.

http://www.blossomheartquilts.com/2012/07/hst-tutorial-and-maths-formula/

I taught math for a short time in SE Michigan, and was told by a couple students they would never need it!

I always would rather have a bit of waste than to make it too small that being said I would try to make it 3" and sliver trim to correct size.

That would be my answer....what an odd size!

The problem with making 4 at a time with this method results in bias edges. Since you say you are a "nervous nelly beginner", do you feel confident to handle the biases, if so, go for it. I see everything as a learning experience if only to say, "well, I won't try that again". Martha McCloskey has a way to make multiples and the sides are all on the straight or crossways grain. Very ingenious. Good luck to you and welcome o the QB. Soon, you will be an old pro.

If you are a newbie, why are you attempting to make them with bias edges?? Just stick to the easy stuff of doing a traditional HST. Is your 2.75" your finished size?? It is easier to know what your finished size is, add an inch and cut that size of square which will produce 2 HSTs. Then you can trim them and they will be perfect.

I agree with ManiacQuilter2. I admire you for attempting something new. As someone else pointed out, in no time at all you will be a pro.

Joanns sells a quilter's calculator that can be purchased for about 20 bucks with coupon. I find this little calculator males math alot easier

Doing the math in my head I'd try the 3 7/8 square to get a 2 3/4 hst.

My brain is full so I won't attempt the math today. I just wanted to suggest that you starch and press the fabric before you cut the squares. It will help with the bias edges. I found that method to not work as well for me because of the stretchy outer sides.