Elements of Geometry |
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Common terms and phrases
42 by half alfo equal alſo alternate angles angle ATD angle G angles equal arc FD bafe Becauſe the lines bifects chord circle circumference compofed cone confequently correfponding cube defcribe draw the line draw the right drawn equal number equal to half equiangular exterior angles fame manner fame parallels fee fig fegment fhall fide AB fide BC fide CD fide FG fides proportional fimilar figures folid content fquare fuppofed furface given line half the arc half the product homologous homologous lines incloſe interfection Let the line line AB line AC line BA line CD line D line FG meaſured 42 meaſured by half muſt parallelogram ABCD phyfical points plane LM point F point of divifion PROP pyramid radii radius rectangle right angles right line ſame ſecond ſpace ſquare tangent Theſe two triangles three fides equal triangle ABC triangle DFG triple
Popular passages
Page 85 - FGL have an angle in one equal to an angle in the other, and their...
Page 31 - Through a given point to draw a line parallel to a given straight line.
Page 3 - The magnitude of an angle does not depend upon the length of its legs, that is, of the straight lines by which it is...
Page 86 - Q. the rectangle of B and C, and R the rectangle of B and D. Then the rectangles P and R, being between the same parallels, are to each other as their bases A and B (th.
Page 15 - ... and D; join C and D cutting AB at E, and the line AB is bisected at E. For C and D being each equally distant from A and B, the line CD must be perpendicular to AB at its middle point (converse of I.
Page 125 - But these two angles are (Defin. 3.) the angles of inclination of the two planes. Therefore the two planes make angles with each other, which are together equal to two right angles.
Page 21 - If a line is perpendicular to one of two parallel lines, it is perpendicular to the other; thus EF (Art.
Page 127 - Hence it follows that the lines BG, AH, are parallel (def. 9). And the line AB being perpendicular to the line AH, is also perpendicular to the parallel line BG (cor th. 12). In like manner it is proved, that the line AB is perpendicular to all other lines which can be drawn from the point B in the plane EF. Therefore the line AB is perpendicular t
Page 88 - Let the four lines meet in a common point, forming at that o point four right angles, and complete the rectangles x, y, z. If the line A be triple of the line B, the line C will be triple of the line D. | * The rectangles .••• and z, being between the same parallels, FI* soi.
Page 122 - CDE, another plane might puss through the point A, to which the line AB would be perpendicular. But this is impossible ; for, since the angles BAG, BAD, are right angles...