RELFE BROTHERS' EUCLID SHEETS.

PROPOSITIONS 1—26, BOOK I, ARE NOW PUBLISHED IN A SIMILAR FORM TO THIS.

PROPOSITION II.

From a given point, to draw a straight line equal to a given straight line.

Because the point is the center of the circle

and because is the center of the circle

,

parts of them are equal; therefore the remainder

is equal to the remainder

wherefore

and

are

; but it has been shewn that is equal to each of them equal to ; and things that are equal to the same thing are equal to

one another; therefore the straight line is equal to point a straight line

Wherefore from the given has been drawn equal to the given straight line

RELFE BROTHERS' EUCLID SHEETS.

PROPOSITIONS 1-26, BOOK I, ARE NOW PUBLISHED IN A SIMILAR FORM TO THIS.

PROPOSITION I.

To describe an equilateral triangle upon a given finite straight line.

the circles cut one another, draw the straight lines

shall be an equilateral triangle.

Because the point

is the center of the circle because the point is the center of the circle it has been proved that

is equal to

; therefore

; but things which are equal to the same thing are equal to one another; therefore

is equal to

; wherefore

are equal to one another: and the triangle

is therefore equilateral, and it is described upon the given straight line

RELFE BROTHERS, 6, CHARTERHOUSE BUILDINGS, LONDON, E.C.