Page:First six books of the elements of Euclid 1847 Byrne.djvu/36

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2

BOOK I. PROP. II. PROB.

ROM a given point (), to draw a ſtraight line equal to a given finite ſtraight line ().

Draw (poſt. 1.), deſcribe (pr. 1.), produce (poſt. 2.), deſcribe (poſt. 3.), and (poſt. 3.); produce (poſt. 2.), then is the line required.

For $=$ (def. 15.),
and $=$ (conſt.), $\therefore$ $=$
(ax. 3.), but (def. 15.) $=$ $=$ ;
$\therefore$ drawn from the given point (),
is equal the given line .

Q.E.D.