A Formal Garden calculator is available for different size and number of blocks for your own project.
Background: Cut 8 half square triangles from 2½ inch strip.
Medium Fabric: Cut 8 half square triangles from 2½ inch strip.
Dark Fabric: Cut 1 square 2½ inches.
Half Square Triangle Instructions
Cutting: Using a side right triangle ruler or template, cut half square triangles. Move ruler/template upside down for next cut when necessary.
Sewing: Sew ¼ inch seam on long side of triangle pair. Press seam to one side.