Question

what is the distance traveled by the lunar station in one orbit?

Answer 1

notice the picture below

then, the diameter made by the orbiting lunar station is 32 + 2548 + 32

or 2612, that means the radius is half that, or 1306, that means one orbit is 

circumference of a circle = C = 2π r, r = 1306, thus C = 2π * 1306