The Elements of Euclid: The Errors, by which Theon, Or Others, Have Long Ago Vitiated These Books, are Corrected, and Some of Euclid's Demonstrations are Restored. Also, The Book of Euclid's Data, in Like Manner Corrected. viz. the first six books, together with the eleventh and twelfthMathew Carey, and sold by J. Conrad & Company, S. F. Bradford, Birch & Small, and Samuel Etheridge. Printed by T. & G. Palmer, 116, High-Street., 1806 - 518 pages |
From inside the book
Results 1-5 of 75
Page 19
... join DC ; there- A D fore , because in the triangles DBC , ACB , DB is equal to AC , and BC common to both , the two sides DB , BC are equal to to the two AC , CB , each to each ; and the angle DBC is equal to the angle ACB ; therefore ...
... join DC ; there- A D fore , because in the triangles DBC , ACB , DB is equal to AC , and BC common to both , the two sides DB , BC are equal to to the two AC , CB , each to each ; and the angle DBC is equal to the angle ACB ; therefore ...
Page 21
... join DE , and upon it describe b an equilateral triangle DEF ; then join AF ; the straight line AF bisects the angle BAC . A b 1. 1 . Because AD is equal to AE , and AF is common to the two triangles DAF , EAF ; the two sides DA , AF ...
... join DE , and upon it describe b an equilateral triangle DEF ; then join AF ; the straight line AF bisects the angle BAC . A b 1. 1 . Because AD is equal to AE , and AF is common to the two triangles DAF , EAF ; the two sides DA , AF ...
Page 26
... join BE and produce it to F , and make EF equal to BE ; join also FC , and produce AC to G. E F Because AE is equal to EC , and BE to EF ; AE , EB are equal to CE , EF , each to each ; and the angle b 15. 1. AEB is equal b to the ...
... join BE and produce it to F , and make EF equal to BE ; join also FC , and produce AC to G. E F Because AE is equal to EC , and BE to EF ; AE , EB are equal to CE , EF , each to each ; and the angle b 15. 1. AEB is equal b to the ...
Page 33
... join AH ; and because BH is equal to EF , and AB to DE ; the two AB , BH are equal to the two DE , EF , each to each ; and they contain equal angles ; therefore the base AH is equal to the base DF , and the triangle ABH to the triangle ...
... join AH ; and because BH is equal to EF , and AB to DE ; the two AB , BH are equal to the two DE , EF , each to each ; and they contain equal angles ; therefore the base AH is equal to the base DF , and the triangle ABH to the triangle ...
Page 38
... join the extremities of two equal and parallel straight lines , towards the same parts , are also themselves equal ... Join BC ; and because AB is parallel to CD , and BC meets C D a 29.1 . them , the alternate angles ABC , BCD are ...
... join the extremities of two equal and parallel straight lines , towards the same parts , are also themselves equal ... Join BC ; and because AB is parallel to CD , and BC meets C D a 29.1 . them , the alternate angles ABC , BCD are ...
Common terms and phrases
altitude angle ABC angle BAC base BC BC is equal BC is given bisected Book XI centre circle ABCD circumference cone cylinder demonstrated described diameter draw drawn equal angles equiangular equimultiples Euclid excess fore given angle given in magnitude given in position given in species given magnitude given point given ratio given straight line gnomon greater join less Let ABC meet multiple opposite parallel parallelogram parallelogram AC perpendicular point F polygon prism proposition pyramid Q. E. D. PROP radius rectangle CB rectangle contained rectilineal figure remaining angle right angles segment sides BA similar solid angle solid parallelepipeds square of AC straight line AB straight line BC tangent THEOR third triangle ABC triplicate ratio vertex wherefore
Popular passages
Page 28 - Any two sides of a triangle are together greater than the third side.
Page 62 - To divide a given straight line into two parts, so that the rectangle contained by the whole, and one of the parts, may be equal to the square of the other part.
Page 28 - IF, from the ends of the side of a triangle, there be drawn two straight lines to a point within the triangle, these shall be less than the other two sides of the triangle, but shall contain a greater angle. Let...
Page 57 - PROP. VIII. THEOR. IF a straight line be divided into any two parts, tour times the rectangle contained by the whole line, and one of the parts, together with the square of the other part, is equal to the square of the straight line which is made up of the whole and that part.
Page 26 - If one side of a triangle be produced, the exterior angle is greater than either of the interior opposite angles.
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 17 - THE angles at the base of an isosceles triangle are equal to one another : and, if the equal sides be produced, the angles upon the other side of the base shall be equal.
Page 189 - In right angled triangles, the rectilineal figure described upon the side opposite to the right angle, is equal to the similar, and similarly described figures upon the sides containing the right angle.
Page 37 - All the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as the figure has sidef. For any rectilineal figure ABCDE can be divided into as many triangles as the figure has sides, by drawing straight lines from a point F within the figure to each of its angles.
Page 178 - Therefore, universally, similar rectilineal figures are to one another in the duplicate ratio of their homologous sides.