Elements of Geometry: Being Chiefly a Selection from Playfair's Geometry |
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Page 17
... angle DBC , or CBD . If there be only one angle at a point , it may be expressed by a letter placed at that point , as the angle at E. 10. When a straight line standing on another straight line makes the adjacent angles equal to each ...
... angle DBC , or CBD . If there be only one angle at a point , it may be expressed by a letter placed at that point , as the angle at E. 10. When a straight line standing on another straight line makes the adjacent angles equal to each ...
Page 19
... equal sides . 28. An isosceles triangle is that which has two sides equal . ΔΔΔ 29. A scalene triangle is that which ... angles , Note . A triangle which has no right angle is often called an oblique angled triangle . ED . 33. Of ...
... equal sides . 28. An isosceles triangle is that which has two sides equal . ΔΔΔ 29. A scalene triangle is that which ... angles , Note . A triangle which has no right angle is often called an oblique angled triangle . ED . 33. Of ...
Page 20
... angles of any quadrilateral figure , or two opposite angles of any polygon , is called a diagonal . ED . 38. In a right angled triangle the side opposite to the right angle ... equal straight lines , and 20 ELEMENTS OF.
... angles of any quadrilateral figure , or two opposite angles of any polygon , is called a diagonal . ED . 38. In a right angled triangle the side opposite to the right angle ... equal straight lines , and 20 ELEMENTS OF.
Page 23
... equal to BC . K H D B A E G F Because the point B is the centre of the circle CGH , BC is equal to BG ( 20 Def ... angles contained by those sides equal to each other ; their third sides will be equal ; and GEOMETRY . 23 BOOK I.
... equal to BC . K H D B A E G F Because the point B is the centre of the circle CGH , BC is equal to BG ( 20 Def ... angles contained by those sides equal to each other ; their third sides will be equal ; and GEOMETRY . 23 BOOK I.
Page 24
... equal ; and their other angles to which the equal sides are opposite will be equal , each to each . * Let ABC , DEF be two triangles , which have the side AB equal to DE , and AC to DF ; and the angle A equal to D ; then the base BC ...
... equal ; and their other angles to which the equal sides are opposite will be equal , each to each . * Let ABC , DEF be two triangles , which have the side AB equal to DE , and AC to DF ; and the angle A equal to D ; then the base BC ...
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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.