<ref target="http://echo.mpiwg-berlin.mpg.de/ECHOdocuView?url=/permanent/library/KN1CRTZ2/&start=280&viewMode=image&pn=285">
f. </ref>
. </s>
<lb/>
<quote xml:lang="lat">
<s xml:space="preserve">
Propositio VI.
<lb/>
Dato triangulo rectangulo, invenire aliud triangulum rectangulum majus, & aeque altum;
ut quod fit sub differentia basium ipsorum & differentia hypotenusarum,
aequale fit dato cuicumque recti-lineo.</s>
</quote>
<lb/>
<quote>
<s xml:space="preserve">
Given a right-angled triangle, to find another larger right-angled triangle, with equal height,
so that the product of the difference of the bases and the difference of the hypotenuses
is equal to a given </s>
</quote>
<s xml:space="preserve">]</s>
</p>
</div>
<head xml:space="preserve" xml:lang="lat">
In prop: 6.
<lb/>
[
<emph style="bf">Translation: </emph>
From proposition 6 of the ]</head>
<p xml:lang="lat">
<s xml:space="preserve">
Data
<lb/>
prima
<lb/>
quarta
<lb/>
quatuor
<lb/>
parallela
<lb/>
Quæsita
<lb/>
continue
<lb/>
[
<emph style="bf">Translation: </emph>
Given
<lb/>
first
<lb/>
fourth
<lb/>
four
<lb/>
parallel
<lb/>
Sought
<lb/>
continued ]</s>
</p>
<p xml:lang="lat">
<s xml:space="preserve">
Conclusio ex inferiore
<lb/>
[
<emph style="bf">Translation: </emph>
Conclusion from the demonstration ]</s>
</p>
<p xml:lang="lat">
<s xml:space="preserve">
Demonstratio per compositionem.
<lb/>
Sint primo constructio quatuor proportionales
<lb/>
per 5
<emph style="super">tam</emph>
prop. […] Unde
<math>
<mstyle>
<mi>B</mi>
<mi>β</mi>
</mstyle>
</math>
<lb/>
est æqualis
<math>
<mstyle>
<mi>A</mi>
<mi>B</mi>
</mstyle>
</math>
. et
<math>
<mstyle>
<mi>β</mi>
<mi>λ</mi>
</mstyle>
</math>
et
<math>
<mstyle>
<mi>A</mi>
<mi>Z</mi>
</mstyle>
</math>
parallelæ. Iam fiat
<math>
<mstyle>
<mi>β</mi>
<mi>D</mi>
</mstyle>
</math>
æqualis
<math>
<mstyle>
<mi>A</mi>
<mi>β</mi>
</mstyle>
</math>
.
<lb/>
et ducatur recta
<math>
<mstyle>
<mi>D</mi>
<mi>μ</mi>
</mstyle>
</math>
<emph style="super">parallela
<math>
<mstyle>
<mi>β</mi>
<mi>α</mi>
</mstyle>
</math>
</emph>
et
<math>
<mstyle>
<mi>β</mi>
<mi>μ</mi>
</mstyle>
</math>
sit parallela
<math>
<mstyle>
<mi>A</mi>
<mi>α</mi>
</mstyle>
</math>
vel
<math>
<mstyle>
<mi>A</mi>
<mi>C</mi>
</mstyle>
</math>
. Ergo angulus
<math>
<mstyle>
<mi>D</mi>
<mi>β</mi>
<mi>μ</mi>
</mstyle>
</math>
æqualis
<math>
<mstyle>
<mi>β</mi>
<mi>A</mi>
<mi>α</mi>
</mstyle>
</math>
.
et
<math>
<mstyle>
<mi>α</mi>
<mi>β</mi>
<mi>A</mi>
</mstyle>
</math>
, angulo
<math>
<mstyle>
<mi>μ</mi>
<mi>D</mi>
<mi>β</mi>
</mstyle>
</math>
, et tertius angulo tertio.
<lb/>
Ergo triangula
<math>
<mstyle>
<mi>A</mi>
<mi>α</mi>
<mi>β</mi>
</mstyle>
</math>
et
<math>
<mstyle>
<mi>D</mi>
<mi>μ</mi>
<mi>β</mi>
</mstyle>
</math>
simila et æqualia. Et producta
<math>
<mstyle>
<mi>D</mi>
<mi>μ</mi>
</mstyle>
</math>
transibit per
<math>
<mstyle>
<mi>C</mi>
</mstyle>
</math>
,
alias
<math>
<mstyle>
<mi>A</mi>
<mi>α</mi>
</mstyle>
</math>
et
<math>
<mstyle>
<mi>α</mi>
<mi>C</mi>
</mstyle>
</math>
non sunt æquales. Sit producta
<math>
<mstyle>
<mi>A</mi>
<mi>γ</mi>
</mstyle>
</math>
versus
<math>
<mstyle>
<mi>E</mi>
</mstyle>
</math>
.
<lb/>
Et ducatur
<math>
<mstyle>
<mi>C</mi>
<mi>E</mi>
</mstyle>
</math>
<emph style="super">parallela
<math>
<mstyle>
<mi>α</mi>
<mi>γ</mi>
</mstyle>
</math>
</emph>
. Sit inde
<math>
<mstyle>
<mi>γ</mi>
<mi>δ</mi>
</mstyle>
</math>
parallela
<math>
<mstyle>
<mi>A</mi>
<mi>Z</mi>
</mstyle>
</math>
.
Ergo anguli
<math>
<mstyle>
<mi>γ</mi>
<mi>δ</mi>
<mi>E</mi>
</mstyle>
</math>
,
<math>
<mstyle>
<mi>A</mi>
<mi>H</mi>
<mi>E</mi>
</mstyle>
</math>
, æqualis, et
<math>
<mstyle>
<mi>A</mi>
<mi>ɛ</mi>
<mi>γ</mi>
</mstyle>
</math>
.
et
<math>
<mstyle>
<mi>γ</mi>
<mi>ɛ</mi>
</mstyle>
</math>
æqualis
<math>
<mstyle>
<mi>δ</mi>
<mi>H</mi>
</mstyle>
</math>
. et
<math>
<mstyle>
<mi>δ</mi>
<mi>E</mi>
</mstyle>
</math>
.
<lb/>
et æqualis
<math>
<mstyle>
<mi>E</mi>
<mi>γ</mi>
</mstyle>
</math>
et
<math>
<mstyle>
<mi>γ</mi>
<mi>A</mi>
</mstyle>
</math>
. et
<math>
<mstyle>
<mi>H</mi>
<mi>λ</mi>
</mstyle>
</math>
æqualis
<math>
<mstyle>
<mi>α</mi>
<mi>ɛ</mi>
</mstyle>
</math>
vel
<math>
<mstyle>
<mi>γ</mi>
<mi>θ</mi>
</mstyle>
</math>
.
Et quia
<math>
<mstyle>
<mi>A</mi>
<mi>β</mi>
</mstyle>
</math>
et
<math>
<mstyle>
<mi>β</mi>
<mi>D</mi>
</mstyle>
</math>
æqualis inter parallelas, æqualis etiam
<math>
<mstyle>
<mi>H</mi>
<mi>λ</mi>
</mstyle>
</math>
et
<math>
<mstyle>
<mi>λ</mi>
<mi>C</mi>
</mstyle>
</math>
.
Conclusio igitur
<lb/>
facile colligitur et manifesta. vel triplex ut
<lb/>
[
<emph style="bf">Translation: </emph>
Demonstration by construction.
<lb/>
Let there be first constructed four proportionals by the 5th proposition.
<lb/>
Whence
<math>
<mstyle>
<mi>B</mi>
<mi>β</mi>
</mstyle>
</math>
is equal to
<math>
<mstyle>
<mi>A</mi>
<mi>B</mi>
</mstyle>
</math>
, and
<math>
<mstyle>
<mi>β</mi>
<mi>λ</mi>
</mstyle>
</math>
and
<math>
<mstyle>
<mi>A</mi>
<mi>Z</mi>
</mstyle>
</math>
are parallel.
<lb/>
Now construct
<math>
<mstyle>
<mi>β</mi>
<mi>D</mi>
</mstyle>
</math>
equal to
<math>
<mstyle>
<mi>A</mi>
<mi>β</mi>
</mstyle>
</math>
, and the line
<math>
<mstyle>
<mi>D</mi>
<mi>μ</mi>
</mstyle>
</math>
parallel to
<math>
<mstyle>
<mi>β</mi>
<mi>α</mi>
</mstyle>
</math>
, and
<math>
<mstyle>
<mi>β</mi>
<mi>μ</mi>
</mstyle>
</math>
is parallel to
<math>
<mstyle>
<mi>A</mi>
<mi>α</mi>
</mstyle>
</math>
or
<math>
<mstyle>
<mi>A</mi>
<mi>C</mi>
</mstyle>
</math>
. Therefore the angule
<math>
<mstyle>
<mi>D</mi>
<mi>β</mi>
<mi>μ</mi>
</mstyle>
</math>
is equal to
<math>
<mstyle>
<mi>β</mi>
<mi>A</mi>
<mi>α</mi>
</mstyle>
</math>
, and
<math>
<mstyle>
<mi>α</mi>
<mi>β</mi>
<mi>A</mi>
</mstyle>
</math>
to angle
<math>
<mstyle>
<mi>μ</mi>
<mi>D</mi>
<mi>β</mi>
</mstyle>
</math>
, and the third angle to the third. Therefore the triangles
<math>
<mstyle>
<mi>A</mi>
<mi>α</mi>
<mi>β</mi>
</mstyle>
</math>
and
<math>
<mstyle>
<mi>D</mi>
<mi>μ</mi>
<mi>β</mi>
</mstyle>
</math>
are similar and qual.
<lb/>
And
<math>
<mstyle>
<mi>D</mi>
<mi>μ</mi>
</mstyle>
</math>
produced will pass through
<math>
<mstyle>
<mi>C</mi>
</mstyle>
</math>
, otherwis
<math>
<mstyle>
<mi>A</mi>
<mi>α</mi>
</mstyle>
</math>
and
<math>
<mstyle>
<mi>α</mi>
<mi>C</mi>
</mstyle>
</math>
are not equal. Let
<math>
<mstyle>
<mi>A</mi>
<mi>γ</mi>
</mstyle>
</math>
be produced towars
<math>
<mstyle>
<mi>E</mi>
</mstyle>
</math>
.
<lb/>
And
<math>
<mstyle>
<mi>C</mi>
<mi>E</mi>
</mstyle>
</math>
is constrcuted parallel to
<math>
<mstyle>
<mi>α</mi>
<mi>γ</mi>
</mstyle>
</math>
. Let
<math>
<mstyle>
<mi>γ</mi>
<mi>δ</mi>
</mstyle>
</math>
be parallel to
<math>
<mstyle>
<mi>A</mi>
<mi>Z</mi>
</mstyle>
</math>
. Therefore angles
<math>
<mstyle>
<mi>γ</mi>
<mi>δ</mi>
<mi>E</mi>
</mstyle>
</math>
and
<math>
<mstyle>
<mi>A</mi>
<mi>H</mi>
<mi>E</mi>
</mstyle>
</math>
are equal, and
<math>
<mstyle>
<mi>A</mi>
<mi>ɛ</mi>
<mi>γ</mi>
</mstyle>
</math>
; and
<math>
<mstyle>
<mi>γ</mi>
<mi>ɛ</mi>
</mstyle>
</math>
is equal to
<math>
<mstyle>
<mi>δ</mi>
<mi>H</mi>
</mstyle>
</math>
and
<math>
<mstyle>
<mi>δ</mi>
<mi>E</mi>
</mstyle>
</math>
; and
<math>
<mstyle>
<mi>E</mi>
<mi>γ</mi>
</mstyle>
</math>
to
<math>
<mstyle>
<mi>γ</mi>
<mi>A</mi>
</mstyle>
</math>
; and
<math>
<mstyle>
<mi>H</mi>
<mi>λ</mi>
</mstyle>
</math>
is equal to
<math>
<mstyle>
<mi>α</mi>
<mi>ɛ</mi>
</mstyle>
</math>
or
<math>
<mstyle>
<mi>γ</mi>
<mi>θ</mi>
</mstyle>
</math>
. And because
<math>
<mstyle>
<mi>A</mi>
<mi>β</mi>
</mstyle>
</math>
and
<math>
<mstyle>
<mi>β</mi>
<mi>D</mi>
</mstyle>
</math>
are equal between parallels,
<math>
<mstyle>
<mi>H</mi>
<mi>λ</mi>
</mstyle>
</math>
and
<math>
<mstyle>
<mi>λ</mi>
<mi>C</mi>
</mstyle>
</math>
are also equal.
<lb/>
Therefore the conclusion is easily gathered and shown, or three times, as ]</s>