The truck squares were 5.5", the yellow strip 1.5". the log cabin strips 2.5" (x3) for a total of 14.5", minus 2" for 4 seams is 12 1/2" blocks. I do remember needing that size ruler to square them. I saw a quilt on a magazine cover with maple leaf blocks set like this. I had to add to the yellow strip before the LC strips to keep the colors contained.