... (3) and they are both concave in the same<direction>, (4) and one of them is contained by the other surface and by the plane having the same limits as itself.229(5) And similarly, the surface ... already possess, on cones and cylinders on the one hand, and on circles and polygons on the other hand, may finally be integrated and brought to bear on the sphere. Following the brief “interlude” ... in the sphere, and < ;its& gt; height equal to the perpendicular drawn from the center of the sphere on one side of the polygon.249Let there be the sphere, and a great circle in it, AB, and...