Commentary on Proposition XI.32¶
Back to Proposition XI.32.
As Clavius observed, Euclid should have said, in applying the parallelogram FH to FG, that it should be applied “in the angle FGH equal to the angle LCG.” Simson is however, I think, hypercritical when he states as regards the completion of the solid GK that it ought to be said, “complete the solid of which the base is FH, and one of its insisting straight lines is FD.” Surely, when we have two faces DG, FH meeting in an edge, to say “complete the solid” is quite sufficient, though the words “on FH as base” might perhaps as well be left out. The same “completion” of a parallelepipedal solid occurs in XI. 31 and 33.