#1Pages 122-124, Striped Trianglesaffects: Quilts in an English Village (ISBN 9781641551502)
Cut strips 5 1/4" wide down the LENGTH of the fabric (along the stripes) and cut 63 triangles at 45 degrees; strips from 3/8 yd yield 1 triangle, fat quarters 2, and 5/8 yd 3.
Official — publisher correction see the source ↗