Wednesday, May 30, 2012

Tutorial-Figuring Setting and Corner Triangles

   It dawned on me while making my Elegant Garden Lost Blocks quilt...

 that there just might be some of you who would like to know the mathematical formula used to figure the setting triangles.  So here goes.  Lay out your blocks, in this case I grabbed some charm squares.
 Figure the FINISHED size of your block.  These 5" charms will finish 4.5".
 Get your calculator and use this formula to figure your setting triangles.  
 Start with the finished size (mine is 4 1/2").
 Times that number by 1.41 
 That will equal 6.345
 Now don't clear the calculator continue to figure your problem.  Take the 6.345 (or number you got from your particular block size) and ADD 1.25.
 This will give you the size of the block you need to cut.  
 My answer came to slightly more than 7 1/2" so I'm going to cut the block at 7 5/8".
I can not stress enough how important starching your fabric is.  These triangles will be cut on the bias making them very stretchy so starching the block before sub cutting is imperative. 
 Cut your block on the diagonal in one direction.
 And then cut in the opposite direction.  Yielding 4 Setting Triangles.  
 Lay out these triangles along the sides and top of your quilt.
Follow the same steps for the Corner Triangles using this formula.
 Using the same 4 1/2" finished block I got the answer of 4" square.  Cut and starch 2 squares.
 Cut each starched square on the diagonal ONCE.  Yielding 2 corner triangles from each block.
 Add these triangles to each of the four corners of your quilt.
 Your results should be this.
I hope you found this tutorial helpful.  Please feel free to link it or become a follower to get all of my blog posts.  Thank you for visiting my blog.  Laural


Sally Hurst said...

Thank you for doing this Lori, as it is confusing. I wonder if you could also tell us what the finished block measurement would be if you are sashing the blocks. Thanks!

~Marica~ said...

Thanks a lot for the tip to get perfect "corner"..

Nice blog you have :)

Margot said...

Obrigada, seus tutoriais são ótimos e bem explicados.