 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 - Σελίδα 103των Edward Atkins - 1874Πλήρης προβολή - Σχετικά με αυτό το βιβλίο
 | James Thomson (LL.D.) - 1837 - 296 σελίδες
...When one straight line standing on another, makes with it two angles which are equal, each of these angles is called a RIGHT ANGLE ; and the straight line which stands on the other is said to be PERPENDICULAR, Or AT RIGHT ANGLES, tO it, or tO be a PERPENDICULAR to it. III. An OBTUSE... | |
 | Euclides - 1838 - 264 σελίδες
...placed at that point; as the angle at E.VIII. 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. IX. An obtuse angle is that which is greater than... | |
 | Euclides - 1841 - 378 σελίδες
...equal* to the £"" * 3. 1. 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: *iODef. therefore the angle GDB is a right angle : but FDB *' is likewise a right angle;... | |
 | John Playfair - 1842 - 332 σελίδες
...ADG is equal (8. 1.) 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 (7. def. 1.) Therefore the angle GDB is a right angle: But FDB is likewise a right angle:... | |
 | Euclides - 1842 - 316 σελίδες
...ADG is equal (8. 1.) 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 (lO.Def. 1.); therefore the angle GDB is a right angle : but FD в is likewise a right... | |
 | Philip Kelland - 1843 - 168 σελίδες
...centre is the angular point, as trigonometers often make it. 7. When a straight line standing on another makes the adjacent angles equal to one another, each...stands on the other is called a perpendicular to it. By looking over the propositions of Euclid's first Book it will be seen that the only definitions which... | |
 | William Pease - 1843 - 80 σελίδες
...intersection of two of its great circles. X. 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. Beginners are apt to suppose that a perpendicular, must be a vertical, or plumb line, which it need... | |
 | Scottish school-book assoc - 1845 - 444 σελίδες
...called simply the »ngle at E, PLANE GEOMETRY. 9. 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 strnight line which stands on the other is called a perpendicular to it. 10. An obtuse angle is that... | |
 | Euclid, James Thomson - 1845 - 382 σελίδες
...line standing on another makes the adjacent angles equal, each of the angles is called a right ample; and the straight line which stands on the other is called a perpendicular to it, and is said to be at right angles to it. 9. An obtuse angle is that which is greater than a right angle.... | |
 | Euclides - 1845 - 546 σελίδες
...ADG is equal to the angle GDB: (i. 8.) 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 FDB is likewise a right... | |
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