To cut half-square triangles, we need to:
Measure and cut the fabric 7/8ᵗʰ of an inch greater than the desired finished measurement.
Use your square quilting ruler to mark along the diagonal of the square.
Use your 1/2 inch quilters rule to mark a line 1/4ᵗʰ of an inch in from the diagonal
Stitch along the parallel lines you marked.
Finally, cut along the diagonal line.
Read more