## The Elements of Euclid: Also the Book of Euclid's Data ...cor. viz. The first six books, together with the eleventh and twelfthF. Wingrave, 1804 - Trigonometry |

### From inside the book

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**angle**DEF , and the**angle**ACB to DFE . For if the triangle ABC be applied to DEF so that the point A may be on D , and the straight line AB upon DE ; the point B shall coincide with the point E ,**because**ABis equal to DE . and AB coin ... Page 11

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**because**in the triangles DBC , ACB , DB is equal to A AC , and BC common to both , the two fides DB , BC are equal to the two AC , CB , each to each ; and the**angle**DBC is D equal to the**angle**ACB ; therefore the base DC is equal to the ... Page 12

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**because**AC is equal to AD in the triangle 2. 5. 1 . ACD , the**angles**ECD , FDC upon the other fide of the base CD are equal to one another ; but the**angle**ECD is greater than the**angle**BCD , wherefore the**angle**CA D FDC is likewife ... Page 14

... the two straight lines ABC , ABD have the fegment AB common to both of them . from the point B draw BE at right

... the two straight lines ABC , ABD have the fegment AB common to both of them . from the point B draw BE at right

**angles**to AB ; and**because**ABC is a straight line , the**angle**CBE is equal to the**angle**EBA , in 14 THE ELEMENTS. Page 16

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**angles**to CD . therefore the**angles**CBE , EBD are two right**angles**2. and**because**CBE is equal to the two**angles**CBA , ABE together ; add the**angle**EBD to each of these equals , therefore the**angles**CBE , EBD are c . 2. Ax . equal to the ...### Common terms and phrases

alſo altitude angle ABC angle BAC baſe BC BC is equal BC is given becauſe the angle becauſe the ratio biſected Book XI cafe cauſe circle ABCD circumference cone conſtruction cylinder demonſtrated deſcribed diameter drawn EFGH equal angles equiangular equimultiples Euclid exceſs fame multiple fame ratio fame reaſon fides fimilar firſt folid angle fore given angle given in magnitude given in poſition given in ſpecies given magnitude given ratio given ſtraight line gnomon greater join leſs likewife oppoſite parallel parallelepipeds parallelogram paſs perpendicular plane angles priſm PROP proportionals Propoſition pyramid rectangle contained rectilineal figure right angles ſame ſecond ſegment ſhall ſhall be equal ſhewn ſide ſolid ſome ſpace ſphere ſquare of AC ſtraight line AC THEOR theſe thoſe thro triangle ABC vertex wherefore

### Popular passages

Page 157 - D ; wherefore the remaining angle at C is equal to the remaining angle at F ; Therefore the triangle ABC is equiangular to the triangle DEF. Next, let each of the angles at C, F be not less than a right angle ; the triangle ABC is also, in this case, equiangular to the triangle DEF.

Page 24 - ... be equal, each to each ; and also the third angle of the one to the third angle of the other. Let ABC, DEF be two triangles which have the angles ABC, ECA equal to the angles DEF, EFD, viz.

Page 1 - The circumference of every circle is supposed to be divided into 360 equal parts called degrees, and each degree into 60 equal parts called minutes, and each minute into 60 equal parts called seconds, and these into thirds, fourths, &c.

Page 45 - If a straight line be divided into any two parts, the rectangle contained by the whole and one of the parts, is equal to the rectangle contained by the two parts, together with the square of the aforesaid part.

Page 73 - THE straight line drawn at right angles to the diameter of a circle, from the extremity of...

Page 163 - If two triangles have one angle of the one equal to one angle of the other and the sides about these equal angles proportional, the triangles are similar.

Page 81 - ELF. Join BC, EF ; and because the circles ABC, DEF are equal, the straight lines drawn from their centres are equal: therefore the two sides BG, GC, are equal to the two EH, HF ; and the angle at G is equal to the angle at H ; therefore the base BC is equal (4.

Page 323 - Equiangular parallelograms have to one another the ratio which is compounded of the ratios of their sides.

Page 80 - EA : and because AD is equal to DC, and DE common to the triangles ADE, CDE, the two sides AD, DE are equal to the two CD, DE, each to each ; and the angle ADE is equal to the angle CDE, for each of them is a right angle ; therefore the base AE is equal (4.

Page 36 - To a given straight line to apply a parallelogram, which shall be equal to a given triangle, and have one of its angles equal to a given rectilineal angle.