Measurement tool for diagonals is wrong

For Pathfinder rules, every other diagonal step is double. For instance, first step is 5 ft, second is 10, third is 5, fourth is 10. Your existing ruler measures all of them as 5, this breaks the pythagorean theorem where the diagonal of a triangle is longer than the 2 sides. a^2 + b^2 = c^2. To best simulate that, we need to include at least an option to change the rules of the ruler. :)

Under Page Settings, select "Pathfinder/3.5E Compatible" for Diagonals. The default is consistent with D&D 4e rules. You can also select Euclidean (which gets actual Euclidean distance rounded to 1 decimal point) or Manhattan (where a diagonal is 2 units, as though you're a cab driver on perpendicular streets trying to reach a diagonal corner).