Measuring with the multiple-size 60-degree rulers is easy! They work perfectly with the hexagon family of templates (Sets G, H and N, Hexagon Ruler, Half-Hexagon Ruler, 60-degree Diamond Ruler). Other equilateral triangle rulers measure the height of the triangle from the center of the bottom to the top point. These rulers measure the triangle on the side. In fact, all From Marti Michell family members are size-defined by the length of the finished side because it is the only measurement that is common to all of the shapes in the family.