After the experiment, it is the most convenient to use the grid, display the grid, align the grid, and then add some points on the line segment, and the points are also aligned with the cross of the grid. If you want to divide it into several optional nodes, you can split them in two.

If you plan to draw three separate line segments at first, draw a line with a total length of 1/3 at the earliest, resize it with the mouse, flip it from one side to the other (and fix the size twice with Ctrl at the same time), and right-click to keep the original one. If you copy other line segments, you can align them.