Books Books
Convertendo, by conversion ; when there are four proportionals, and it is inferred, that the first is to its excess above the second, as the third to its excess above the fourth.
A Supplement to the Elements of Euclid - Page 288
by Daniel Cresswell - 1819 - 410 pages

## The Elements of Euclid for the Use of Schools and Colleges: Comprising the ...

Euclid, Isaac Todhunter - Euclid's Elements - 1883 - 428 pages
...V. 17. 17. Convertendo, by conversion; when there are four proportionals, and it is inferred, that the first is to its excess above the second, as the third is to its excess above the fourth. VE 18. Ex (equali distantia, or ex cequo, from equality of distance...

## The Harpur Euclid: An Edition of Euclid's Elements

Edward Mann Langley, W. Seys Phillips - 1890 - 538 pages
...17. ' Convertendo,' by conversion ; used when there are four proportionals, and it is inferred that the first is to its excess above the second as the third is to its excess above the fourth. It is demonstrated in ' V. E ' that if A+ B : B : : C+ D : D, then...

## Books 3-9

Euclid - Mathematics, Greek - 1908 - 456 pages
...Proposition E (containing a proof already given by Clavius), on Props. 17 and 18. Prop. E is as follows. If four magnitudes be proportionals, they are also...first is to its excess above the second as the third is to its excess above the fourth. Let AB be to BE as CD to DF: then BA is to AE as DC to CF. Because...

## The Thirteen Books of Euclid's Elements

Euclid - 452 pages
...Proposition £ (containing a proof already given by Clavius), on Props. 17 and 18. Prop. E is as follows. If four magnitudes be proportionals, they are also...first is to its excess above the second as the third is to its excess above the fourth. Let AB be to BE as CD to DF: then BA is to AE as DC to CF. Because...