Dome Radius
The Dome Radius is simply
the radius of the sphere in which the geodesic dome you are designing
is inscribed. A geodesic dome is an approximation to a sphere.
Each vertex in the dome lies on the surface of that sphere. The
distance from the center of this sphere to the outside (i.e.,
to a vertex) is the radius:
The distance from one side of the dome
to the other, the diameter, is twice the radius:
D = 2r