... equal to the surface of one of the cones containing the rhom-bus,189 and a height equal to the perpendicular drawn from the vertex of the other cone to a side of the other cone.190Let there be ... <is> the circle A, and let the radius be , and let be equal to the side of the cone, and <let>E < ;be& gt; a mean proportional between , , and let the circle B have the radius equal to ... the surface of the figure in the other hemisphere, too, is smaller than the surface of the hemisphere;230(6) so the whole surface of the figure in the sphere, too, is smaller than the surface of the...