[Yoda]

Those are different from the that of the plane line.

Look at 2-C-1.

I realize Yoda says you can trace the Low Point Plane Line, but I would submit that this trace would put you to the outside of the point of impact which doesn't seem to be a desireable thing at least when at first mastering this.

Plane Line definition, see 10-5. Baseline of the Incline Plane is the plane line which is not as shown in 10-5 the other lines.

Simply put starting at the feet looking down with the ball located behind the low point you have
a. Stance Line
b. Plane Line
c. Impact Line
d. Line of Flight
e. Low Point Line

Remember, Martee, don't confuse the Clubshaft's Impact Plane Line with the Sweetspot's Impact Plane Line. These are quite different!

I sense you are about to have a major "Aha!" moment.