jdb2 08-01-2024, 12:21 PM
In The Upwelling, specifically in one of the images of *the lower left hand portion* of the regular septagon in the New Jersey pine barrens or a similar image of the regular septagon that encircles the village on/near "the Mountain" (at least in the Amazon Kindle ebook version -- I assume it's the same in the print version), the image contains a "120" degree label in the lower left hand corner, inside the septagon, which is an internal angle for a regular hexagon not a regular septagon.
The general formula for the internal angles of an regular n-gon is : θ = 180 - 360/n , where n is the number of sides (or, if you prefer radians, θ = π - 2π/n). If the angle is 120 degrees ( θ ), then we have : n = 360/(180 - θ) = 6 sides.
The internal angles of a regular septagon are : 128 + 4/7 or approx. 128.57 ( or, in radians : 5π/7 )
I don't remember if the 120 degree angle error is only present in one of the images of the lower left hand fragment of a regular septagon, or if it is also present in the book text. ( EDIT : Not present in book text )
Also, I don't know if this has been covered before -- if it has then I apologize for the redundancy.
jdb2