Elements of Geometry: Being Chiefly a Selection from Playfair's Geometry |
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... lines which intersect each other cannot be both parallel to the same straight line . For 4 Def read Cor . 3 Def . After AF put , For agles read angles For first comma read = After line 1 read AC , BD bisect each other , & For angled ...
... lines which intersect each other cannot be both parallel to the same straight line . For 4 Def read Cor . 3 Def . After AF put , For agles read angles For first comma read = After line 1 read AC , BD bisect each other , & For angled ...
Page 18
... parallel lines are equidistant . For they neither accede to , nor recede from each other . ED . 16. Cor . 2. If two straight lines be perpendicular to the same straight line , they are parallel to each other . For they have no ...
... parallel lines are equidistant . For they neither accede to , nor recede from each other . ED . 16. Cor . 2. If two straight lines be perpendicular to the same straight line , they are parallel to each other . For they have no ...
Page 20
... sides parallel . 36. A trapezium is a four - sided figure , of which the opposite sides are not parallel ; and the diagonal is the straight line joining two of its opposite angles . ED . 37. A straight line joining two opposite angles ...
... sides parallel . 36. A trapezium is a four - sided figure , of which the opposite sides are not parallel ; and the diagonal is the straight line joining two of its opposite angles . ED . 37. A straight line joining two opposite angles ...
Page 39
... lines are parallel . See Appendix to Book I. Let the straight line EF , which intersects the two straight lines AB , CD , make the alternate angles AEF , EFD equal to each other ; AB is parallel to CD . For if AB and CD be not parallel ...
... lines are parallel . See Appendix to Book I. Let the straight line EF , which intersects the two straight lines AB , CD , make the alternate angles AEF , EFD equal to each other ; AB is parallel to CD . For if AB and CD be not parallel ...
Page 40
... line & c . Q. E. D. Cor . Straight lines which are perpendic- ular to the same straight line , and in the same plane with it , are parallel to one another . If AB and CD be perp . to EF , the angles at E and F will be right angles ( 10 ...
... line & c . Q. E. D. Cor . Straight lines which are perpendic- ular to the same straight line , and in the same plane with it , are parallel to one another . If AB and CD be perp . to EF , the angles at E and F will be right angles ( 10 ...
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Elements of Geometry: Being Chiefly a Selection From Playfair's Geometry John Playfair No preview available - 2023 |
Elements of Geometry: Being Chiefly a Selection From Playfair's Geometry John Playfair No preview available - 2023 |
Common terms and phrases
ABC is equal ABCD alternate angles angle ABC angle ACB angle BAC angles AGH angles equal base ABC bases and altitudes bisect centre chord circumference cone Consequently cylinder demonstrations described diagonals diameter divided draw equal angles equal arches equal bases equal circles equal to AC equiangular Euclid's Euclid's Elements exterior angle fore four quantities four right angles geometry given point given straight line gles greater Hence homologous sides intersect KLMN Let ABC meet opposite angles opposite side paral parallel lines parallel to CD parallelogram parallelopipeds perp perpendicular plane polygon prism Prop pyramid Q. E. D. COR Q. E. D. PROPOSITION radius rectangle contained right angled triangle Scholium segments semicircle side AC similar similar triangles solid square straight line &c subtended tangent THEOREM triangle ABC vertex wherefore
Popular passages
Page 36 - Any two sides of a triangle are together greater than the third side.
Page 80 - If a straight line be divided into any two parts, the square of the whole line is equal to the squares of the two parts, together with twice the rectangle contained by the parts.
Page 42 - To draw a straight line through a given point parallel to a given straight line. Let A be the given point, and BC the given straight line...
Page 30 - To bisect a given finite straight line, that is, to divide it into two equal parts. Let AB be the given straight line : it is required to divide it intotwo equal parts.
Page 20 - LET it be granted that a straight line may be drawn from any one point to any other point.
Page 38 - Problem. At a given point in a given straight line to make a rectilineal angle equal to a given rectilineal angle.
Page 113 - Wherefore also the angle BAD is equal to the angle CAD : Therefore the angle BAC is cut into two equal angles by the straight line AD.
Page 24 - DE ; the point B shall coincide with the point E, because AB is equal to DE; and AB coinciding with DE, AC shall coincide...
Page 36 - The greater angle of every triangle is subtended by the greater side, or has the greater side opposite to it.