H
E
E
L
E
M
E
N
T
S
it will either fall within it [as CGD], or outside it: which is impossible [III.23]
or
it will fall awry, as CGD, and a circle cuts a circle at more points than two: which is impossible. [III.10]
therefore, if the straight line AB be applied to CD,
the segment AEB will not fail to coincide with CFD also;
Being what it was required to prove.
