The Path-Way to Knowledg, Containing the First Principles of GeometrieRecord, Robert
Science
The Path-Way to Knowledg, Containing the First Principles of Geometrie
Record, Robert
Geometry -- Early works to 1800
A.B, is the lyne assigned. E. is the middle pricke of A.B, B.C.
is the plumb line or perpendicular, made of the halfe of A.B,
equall to A.E, other B.E, the byas line is C.A, from whiche I
cut a peece, that is C.D, equall to C.B, and accordyng to the
lengthe lo the peece that remaineth (whiche is D.A,) I doo
deuide the line A.B, at whiche diuision I set F. Now say I, that
this line A.B, (w^{ch} was assigned vnto me) is so diuided in
this point F, y^t y^e square of y^e hole line A.B, & of the one
portiõ (y^t is F.B, the lesser part) is equall to the square of
the other parte, whiche is F.A, and is the greater part of the
first line. The profe of this equalitie shall you learne by the
.xl. Theoreme.
[Transcriber’s Note:
There are two ways to make this Example work:
--transpose E and F in the illustration, and change one
occurrence of E to F in the text (“at whiche diuision I
set...”), _or_:
--keep the illustration as printed, and transpose all other
occurrences of E and F in the text.]
THE .XIX. CONCLVSION.
To make a square quadrate equall to any right lined figure
appoincted.
First make a likeiamme equall to that right lined figure, with a
right angle, accordyng to the .xi. conclusion, then consider the
likeiamme, whether it haue all his sides equall, or not: for yf
they be all equall, then haue you doone your conclusion. but and
if the sides be not all equall, then shall you make one right
line iuste as long as two of those vnequall sides, that line
shall you deuide in the middle, and on that pricke drawe half a
circle, then cutte from that diameter of the halfe circle a
certayne portion equall to the one side of the likeiamme, and
from that pointe of diuision shall you erecte a perpendicular,
which shall touche the edge of the circle. And that
perpendicular shall be the iuste side of the square quadrate,
equall both to the lykeiamme, and also to the right lined figure
appointed, as the conclusion willed.
_Example._
[Illustration]
K, is the right lined figure appointed, and B.C.D.E, is the
likeiãme, with right angles equall vnto K, but because that this
likeiamme is not a square quadrate, I must turne it into such
one after this sort, I shall make one right line, as long as
.ij. vnequall sides of the likeiãme, that line here is F.G,
whiche is equall to B.C, and C.E. Then part I that line in the
middle in the pricke M, and on that pricke I make halfe a
circle, accordyng to the length of the diameter F.G. Afterward I
cut awaie a peece from F.G, equall to C.E, markyng that point
with H. And on that pricke I erecte a perpendicular H.K, whiche
is the iust side to the square quadrate that I seke for,
therfore accordyng to the doctrine of the .x. conclusion, of the
lyne I doe make a square quadrate, and so haue I attained the
practise of this conclusion.
THE .XX. CONCLVSION.
When any .ij. square quadrates are set forth, how you maie
make one equall to them bothe.
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