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A collection of classical geometry in computable formats along with code and diagrams.
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Euclid Book 5
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Euclid Book 5 Proposition 9a
Statement
T
w
o
m
a
g
n
i
t
u
d
e
s
w
h
i
c
h
h
a
v
e
t
h
e
s
a
m
e
r
a
t
i
o
t
o
a
t
h
i
r
d
(
A
B
E
F
C
D
E
F
)
e
q
u
a
l
o
n
e
a
n
o
t
h
e
r
(
A
B
C
D
)
.
Computational Explanation
Explanations
For let each of the magnitudes
A
,
B
have the same ratio to
C
; I say that
A
is equal to
B
.
For, otherwise, each of the magnitudes
A
,
B
would not have had the same ratio to
C
;
[
V
.
8
]
but it has; therefore
A
is equal to
B
.
Classes
Euclid's Elements
Theorems
Geometric Algebra
EuclidBook5
Related Theorems
EuclidBook5Proposition7
EuclidBook5Proposition9b