Commentary on Proposition XII.13¶
Back to Proposition XII.13.
It is not necessary to reproduce the proof, as it follows exactly the method of VI. 1 and XI. 25.
The fact that cylinders described about axes of equal length and having equal bases are equal is inferred from XII. 11 to the effect that cylinders of equal height are to one another as their bases. That, of two cylinders with unequal axes but equal bases, the greater is that which has the longer axis is of course obvious either by application or by cutting off from the cylinder with the longer axis a cylinder with an axis of the same length as that of the other given cylinder.