 When a straight line standing on another straight line makes the adjacent angles equal to one another, each of the angles is called a right angle; and the straight line which stands on the other is called a perpendicular to it.  Pure mathematics - Page 103by Edward Atkins - 1874Full view - About this book
 | Euclides - 1852 - 152 pages
...AC or EF than BA does.] B 2 BOOK I. BOOK I. When a straight line standing on another straight line makes the adjacent angles equal to one another, each...stands on the other is called a perpendicular to it. [That there may be two such angles equal, may be exhibited by the following figures: DC meets the right... | |
 | Royal Military Academy, Woolwich - Mathematics - 1853 - 400 pages
...ADG is equal (8. i.) to the angle GDB : but when a straight line standing upon another straight line makes the adjacent angles equal to one another, each of the angles is a right angle (10 Def. i.); therefore the angle GDB is a right angle : But FDB is likewise a (Constr.)... | |
 | Euclides - 1853 - 146 pages
...The angle ADG is equal to the angle GDB: but when a straight line standing upon another straight line makes the adjacent angles equal to one another, each of the angles is a right angle (I. Def. 10.); therefore 2. The angle GDB is a right angle: but FDB is likewise (Constr.)... | |
 | Euclides - Geometry - 1853 - 176 pages
...adg is equal (i. 8) to the angle gd b' But when a straight line standing upon another straight line makes the adjacent angles equal to one another, each of the angles is a right angle (i. def. 10) : therefore the angle gdb is a right angle : but f db is likewise a right... | |
 | William Somerville Orr - Science - 1854 - 534 pages
...straight line (AB) standing on another straight line (CD) makes the adjacent angles (А В С, А В D) equal to one another, each of the angles is called a right angle ; and the straight lines are said to be perpendicular to each other. Thus the two lines, AB, CD, are perpendicular to... | |
 | Euclides - 1855 - 270 pages
...line standing on another straight line makes the adjacent angles equal to one another, each of these angles is called a right angle ; and the straight...stands on the other is called a perpendicular to it. By borrowing the terms vertical and horizontal from the language of Physics, we may define a right... | |
 | Robert Rawson - 1856 - 178 pages
...letter placed at that point ; as the angle at E." When a straight line standing on another straight line makes the adjacent angles equal to one another, each...stands on the other is called a perpendicular to it. XL An obtuse angle is that which is greater than a right angle. xn. An acute angle is that which is... | |
 | Euclides - 1856 - 168 pages
...When a straight line standing on another straight line makes the adjacent angles equal to each other, each of the angles is called a right angle, and the...straight line which stands on the other is called perpendicular. PROPOSITIONS, i. Straight lines from the same point and in the same direction coincide.... | |
 | William Ezra Worthen - Architectural drawing - 1857 - 650 pages
...letter placed at that point ; as the angle at E.' When a straight line standing on another straight line makes the adjacent angles equal to one another, each...angles is called a right angle ; and the straight lines are said to be perpendicular to each other (fig. 3). An obtuse angle is that which is greater... | |
 | W.E. WORTHEN - 1857 - 600 pages
...letter placed at that point; as the angle at E.' When a straight line standing on another straight line makes the adjacent angles equal to one another, each...the angles is called a right angle; and the straight lines are said to be perpendicular to each other (fig. 3). An obtuse <mgle is that which is greater... | |
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