NOT KNOWN FACTUAL STATEMENTS ABOUT ONE UP MUSHROOM

The "base radius" of a circular cone is definitely the radius of its base; usually this is simply called the radius on the cone. The aperture of the right circular cone is the maximum angle between two generatrix traces; if the generatrix would make an angle θ to your axis, the aperture is twoθ. In optics, the angle θ is known as the half-angle