If I have ... for instance a 7" square ... and I want to turn it sideways .... how do I calculate how large to cut the triangles I need to sew onto the side? i could get one side but I need the other two sides as well. Please help???????

I don't get what you mean turning it sideways....? Sorry

I googled setting triangles formula and got this:

Quilt blocks set "on point" are sewn in diagonal rows beginning in a corner (the top left corner). The first row will be one block with the second row having three blocks, each row is completed with a setting triangle Two blocks can be used in this first row, if you prefer, with the second row having four blocks, the third row six blocks, etc. As you see, whichever setting you prefer, the number of blocks in the diagonal rows increases by two in each row. Add rows until you reach the width you need. The rows will decrease by two as you complete the top. Each row is completed on both ends with a setting triangle.
To determine the size of this triangle, there is a simple formula that works no matter what size the quilt block.

The formula: Size of the block times 1.414, then add 1 1/4 inches.


For a 6 inch block: 6 x 1.414 = 8.484 or 8 1/2 inches. Add the 1 1/4 for seam allowances = 9 3/4 inches. This would be the size of a square block needed to cut setting triangles for a 6 inch block. Use the same formula for your size block.
Cut a strip WOF the measurement you just figured, cut squares that same measurement. Subcut with an X. That will give 4 setting triangles from each square. Mark the outer edges of these triangles. Two of these outer edges are straight of grain and and the other two are cross grain.

Read more at Suite101: Quilt Construction: Taking the Mystery Out of Setting Triangles http://www.suite101.com/article.cfm/...#ixzz0q5eufUxJ


Is this what you meant?

Try using a sheet of paper to help with your calculations - I am a very visual person, so I have to draw things out a lot when I need to see something.

thanks for the info and link

7 inch x 1.41 = 9.87 + 1.25 = 11.12
I'd round it up to a 12 inch block and cut it on the diagonal both ways and you will have 4 triangles. Sew one triangle to each corner.
Square up the block and you are done.

I'm not sure what you mean when you said you could get one but need two more. You need 4 for each 7 inch block.

The formula is the way to go if that is what you meant.

are the figures you use for illustration 6", 7" block etc
the finished or unfinished size of the initial block.

For a 7" square unfinished 9 7/8", 7 1/2" unfinished would be 10 5/8".

Hope this helps. :-D

Thanks to everyone that has chimed in with assistance on this matter. I still find it confusing but not quite as confusing as before.

http://www.quiltville.com/onpointmath.shtml
for putting blocks on point

Oh thank you!!! I freeze whenever I have to figure these things out :D