USA Trains Track G Scale

The track seems wrong. 81600 is 48" radius, 96" diameter and should need 16 pieces for a circle, so 22.5 degrees. But its twice that in the editor and shows 30 degrees.

81100 should be 24" radius, 48" diameter and comes up twice that. I am trying to represent 81600 so using this is okay but the count of the pieces required is off then.