I compared two of my triangles rulers against the 60 degrees on my 6"x24" ruler. I found that the Tri Tool by Darlene Zimmerman was 6.5" in height but was NOT 60 degrees. My Clear View Triangle by Sara Nephew was 6" in height and lined up perfect with the 60 degree line on my ruler. That really surprised me!! I have been using my Tri Tool because the markings are easier to read and has the tip at the top cut off for precise piecing.