A = Medium (Blue)
B = Medium (Green)
C = Light (White)

Cut 4 3" squares of color A (blue)

Cut 4 3.5" squares of color A (blue)
Cut 4 3.5" squares of color B (green)
Cut 4 3.5" squares of color C (white)

Cut these 3.5" squares on the diagonals to make triangles
Sew together 4 sets of triangles using colors A+B (Blue and Green)
Sew together 4 sets of triangles using colors B+C (Green and White)
Sew together 4 sets of triangles using colors C+A (White and Blue)

These should make 3" squares

Arrange squares in the pattern shown above and sew together the blocks to make the Boise block.