Geometry elements. (Color online) Pictorial view of (a) a carbon disk composed of six wedge sections of angle π/3, then (b) the removal of a wedge sections from the disk, and (c) by folding, it is constructed as a cone. Geometrical elements: generatrix rD, height hc, base radius rc, and apex opening angle 2θ, where sinθ=1−nw/6.
Ulloa et al. Nanoscale Research Letters 2013 8:384 doi:10.1186/1556-276X-8-384