Estimating with a circle with end points at 0, 600yds and the 3rd pt as (342,2.9) [the numbers from the above post] the arc length is 600.04 yds. or 600yds + 1.44"
My estimate turns out to be a whole 1.5" extra on the 600 yards.
My circle estimate was 1.44"
Pretty close for the 2 methods.