Euclid's Elements: Or, Second Lessons in Geometry,in the Order of Simson's and Playfair's Editions ... |
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Page 8
... rectangle , has four right angles , and its opposite sides equal and parallel . 32. A rhombus has four equal sides , of which the opposite are paral- lel ; and four oblique angles , of which the opposite are equal . 33. A rhomboid has ...
... rectangle , has four right angles , and its opposite sides equal and parallel . 32. A rhombus has four equal sides , of which the opposite are paral- lel ; and four oblique angles , of which the opposite are equal . 33. A rhomboid has ...
Page 10
... rectangles 32. Rhombus BEFG B 14. Centre CE C 15. Radius CB , CE , & c . 16. Diameter of circle or square , AB , DH . 17. Semicircle ADB . 18. Arc and chord AH . 19. Sector DCI . 20. Segment ADG . 21. Rectilineal figures . 22 ...
... rectangles 32. Rhombus BEFG B 14. Centre CE C 15. Radius CB , CE , & c . 16. Diameter of circle or square , AB , DH . 17. Semicircle ADB . 18. Arc and chord AH . 19. Sector DCI . 20. Segment ADG . 21. Rectilineal figures . 22 ...
Page 32
... rectangle is a superficies contained under two straight lines at right angles to each other : if the lines are equal , the figure is a square ; if unequal , the figure is an oblong ; and in either case , it is a right angled ...
... rectangle is a superficies contained under two straight lines at right angles to each other : if the lines are equal , the figure is a square ; if unequal , the figure is an oblong ; and in either case , it is a right angled ...
Page 33
... rectangle BH contains the three rectangles BK , DL , EH ; and BH is the rectangle of BG and BC : and , since BG , DK , EL are each of them equal to A ( d ) , therefore AXBD equals BK , AXDE equals DL , and AXEC equals EH ; but BD , DE ...
... rectangle BH contains the three rectangles BK , DL , EH ; and BH is the rectangle of BG and BC : and , since BG , DK , EL are each of them equal to A ( d ) , therefore AXBD equals BK , AXDE equals DL , and AXEC equals EH ; but BD , DE ...
Page 34
... rectangle of AC and CG , or CB ; also , that GE is the rectangle of GF and GK , which are equal to AC and CB . Now the two squares and two rectangles make up the square of AB . Wherefore , the square , & c . Recite ( a ) p . 46 ; ( e ) ...
... rectangle of AC and CG , or CB ; also , that GE is the rectangle of GF and GK , which are equal to AC and CB . Now the two squares and two rectangles make up the square of AB . Wherefore , the square , & c . Recite ( a ) p . 46 ; ( e ) ...
Other editions - View all
Euclid's Elements, Or Second Lessons in Geometry, in the Order of Simson's ... D. M'Curdy No preview available - 2017 |
Euclid's Elements, Or Second Lessons in Geometry, in the Order of Simson's ... D. M'Curdy No preview available - 2017 |
Common terms and phrases
ABCD alternate angles angle ACD angles ABC angles equal antecedents Argument base BC bisected centre Chart chord circle ABC circumference Constr Denison Olmsted diameter draw drawn equal angles equal arcs equal radii equal sides equals the squares equi equiangular equilateral equilateral polygon equimultiples exterior angle fore Geometry given circle given rectilineal given straight line gles gnomon greater half inscribed isosceles isosceles triangle join less meet multiple opposite angles parallelogram parallelopipeds pentagon perimeter perpendicular plane polygon produced Q. E. D. Recite radius ratio rectangle rectangle contained rectilineal figure School segment semicircle similar similar triangles sine square of AC tangent touches the circle triangle ABC unequal Wherefore
Popular passages
Page 90 - If two triangles have one angle of the one equal to one angle of the other, and the sides about the equal angles proportionals, the triangles shall be equiangular, and shall have those angles equal which are opposite to the homologous sides.
Page 117 - In the same way it may be proved that a : b : : sin. A : sin. B, and these two proportions may be written a : 6 : c : : sin. A : sin. B : sin. C. THEOREM III. t8. In any plane triangle, the sum of any two sides is to their difference as the tangent of half the sum of the opposite angles is to the tangent of half their difference. By Theorem II. we have a : b : : sin. A : sin. B.
Page 92 - IN a right-angled triangle, if a perpendicular be drawn from the right angle to the base, the triangles on each side of it are similar to the whole triangle, and to one another.
Page 79 - THEOREM. lf the first has to the second the same ratio which the third has to the fourth, but the third to the fourth, a greater ratio than the fifth has to the sixth ; the first shall also have to the second a greater ratio than the fifth, has to the sixth.
Page 87 - If a straight line be drawn parallel to one of the sides of a triangle, it shall cut the other sides, or those sides produced, proportionally...
Page 26 - Triangles upon equal bases, and between the same parallels, are equal to one another.
Page 133 - If a straight line stand at right angles to each of two straight lines at the point of their intersection, it shall also be at right angles to the plane which passes through them, that is, to the plane in which they are.
Page 13 - AB be the greater, and from it cut (3. 1.) off DB equal to AC the less, and join DC ; therefore, because A in the triangles DBC, ACB, DB is equal to AC, and BC common to both, the two sides DB, BC are equal to the two AC, CB. each to each ; and the angle DBC is equal to the angle ACB; therefore the base DC is equal to the base AB, and the triangle DBC is< equal to the triangle (4. 1.) ACB, the less to 'the greater; which is absurd.
Page 71 - If the first magnitude be the same multiple of the second that the third is of the fourth, and the fifth the same multiple of the second that the sixth is of the fourth ; then shall...
Page 83 - IF there be any number of magnitudes, and as many others, which, taken two and two, in a cross order, have the same ratio; the first shall have to the last of the first magnitudes the same ratio which the first of the others has to the last. NB This is usually cited by the words