You’re misinterpreting the lines. Each number only corresponds to the line perpendicular to the 100 point on their axis, and each line only corresponds to one number, not the 2 it looks like it connects to.
So for example, if you’re looking at the middle-top point of the “clay loam” category, right above the ‘l’, you get 30% sand/40% clay/30% silt.
You’re misinterpreting the lines. Each number only corresponds to the line perpendicular to the 100 point on their axis, and each line only corresponds to one number, not the 2 it looks like it connects to.
So for example, if you’re looking at the middle-top point of the “clay loam” category, right above the ‘l’, you get 30% sand/40% clay/30% silt.