Quilt in a Day Forums

I am in desperate need of help! I adore piecing stars, but I cannot get my head around the maths involved in creating the corner and setting squares and triangles. please can anyone help me. I really want to understand the maths so that I can cut the right size no matter what size star I am making. I did admittedly spend hours today trying to work it out on long diamonds 1" wide today, which was stupidly hard! Thanks. - suzy

Hoping this will help you.

Corner Triangles
Take the finished block size and divide by 1.414
Note: Round up to the nearest dimension on the ruler.
Add 7/8" to that number

Cut two squares the size determined above.
Cut each square in half diagonally for the four corner triangles.

Example #1:
Finished block size = 12"
12 / 1.414 = 8.486 (Round to 8.5 = 8-1/2")
8-1/2" + 7/8" = 9-3/8" squares to cut for Corner Triangles

Example#2:
Finished block size = 6"
6 / 1.414 = 4.243 (Round to 4.25 = 4-1/4")
4-1/4" + 7/8" = 5-1/8" squares to cut for Corner Triangles

Side Triangles
Take the finished block size and multiply by 1.414
Note: Round up to the nearest dimension on the ruler.
Add 1-1/4" to that number for the correct size to cut squares for side triangles.

Cut this square in half diagonally twice with an X to produce four Side Triangles.
Cut one square for every four side trinagles needed for the quilt setting.
Example#3:
Finished block size = 12"
12 x 1.414 = 16.96 (Round to 17 = 17")
17" + 1-1/4" = 18-1/4" squares to cut for Side Triangles

Example#4:
Finished block size = 6"
6 x 1.414 = 8.48 (Round to 8.5 = 8-1/2")
8-1/2" + 1-1/4" = 9-3/4" squares to cut fo side triangles