citruscountyquilter

I always make my squares for half square triangles 1" larger than the finished block and then trim. I have two rulers that I use depending on which one I find first. One is a Quilt in a Day ruler that is square but you trim your half square triangle with it before you open it up so there are fewer cuts. Lay the marking on the seam line and cut the two exposed edges to square the triangle. The other method is to press the half square triangle square open and then place a square ruler with the 45 degree angle line running along the seam line. Get it as near two edges as you can with fabric under the ruler and trim the excess. Turn the square around and do the same to the two remaining sides except this time put the markings of the ruler that you want your half square triangle to be along the edges you just cut, again with the 45 degree line on the ruler along the seam line and trim the excess off the two remaining edges. With either of these methods there isn't much overage to trim, usually just slivers but you end up with true half square triangles every time. My avatar is a quilt made almost entirely of half square triangles which I did this way.

ManiacQuilter2

Cedar. It is a simple fact of geometry something to do with angles and length. I don't remember why (was over 46 years ago I took a class in geometry) just that it is a fact of life. Just keep it simple and round up an 1/8" then trim after you have pressed them. Have fun.

Geri B

.....and to think while in school thinking when in my life will I ever need this fraction stuff!

nabobw

I do not cut 7/8 but round it up then trim to the size it is suppose to be. To often the 7/8 cut is small. I have heard this so many time that is why I round it up.

ligia

Thanks for the laugh !

pokeygirl

Watch Jenny Doan's video and learn the easy way. Math and I don't get along. LOL

bigsister63

Sound like we are all a little confused as to what you are talking about. I suspect it is not HST but as you mentioned Square-in a Square. Do you want your center square to be on- point or do you want the block to be square? If it is to be square then I would just do sashing around the block. If you want the center block to be on point then you do need to make "setting" triangles for the corners- this is an entirely different calculation than for HST. Check the internet for " calculations for setting triangles" to see how to make these. This is not the "7/8 rule" that is used for HST. .

Here is Bonnie hunter's version: http://www.stcroixquilters.com/setting%20triangles.htm

quilter68

Dear Cedar,

About your HST issue. The first part is that there is not a 3/8in. left over. The measure is not 10/8ths.; It is 8/8ths. So 7/8th would leave a sliver of 1/8th . Hope this helps you,

quilter 68 who is now 72

Quilt30

If you draw a square (any size) then draw a line diagonally then add 1/4 seam allowance all around, then measure from corner to tip you will see why the 7/8 inch is added. It is because of the angle. I had to do this many years ago to also understand. This is only for half square triangles.

Cedar

I wanted to thank everyone who's been replying and trying to help. I have been checking measurements on right triangles and the hypotinous is 7/8 bigger, although is seems different than what I'm remembering from high school geometry.

PianoDebbie -- your square in a square link was great. It was a huge help.

Possibly silly question -- when connecting a triangle to a rectangle do you match them on he edge or do you center them? I think I just figured out centering them was important.

So I've sucessfully designed and pieced my first block. It's a little wonky in a couple places, but its improving.