Quarter-Square Triangles

There are a bazillion blogs for how to calculate quarter-square triangles, but I'll add mine out there, too. Simply take the finished size of the square you want and add 1-1/4" to it.

Back up a step: What's a quarter-square triangle? A quarter-square triangle is a square that's made up of four triangles. When using two fabrics the resulting square looks like an hour glass.

Here's a quick tut on making a 12" Ohio Star block which uses 4 quarter-square triangles:

1. Cut the following shapes from two different colors of fabric:
Fabric #1:
2, 5-1/4" squares, cut in half diagonally twice (see first photo below)
4, 4-1/2" squares

Fabric #2:
2, 5-1/4" squares, cut in half diagonally twice (see first photo below)
1, 4-1/2" square

2. Layout the fabrics in the following Ohio Star pattern:

3. Pin and sew one half of the quarter-square triangle units together. Press the seams to the darker fabric then trim off the dog ears:
4. Butt the seams up to each other and sew the two halves together:
5. Press the seams to one side then trim off the dog ears. The units should measure 4-1/2":

6. Once more, layout the individual units in the following pattern. Assemble the block as you would any 9-patch block.7. The resulting block should measure exactly 12-1/2" square.