| John Playfair - 1819 - 317 pages
...contained by BD, CB is called the angle DBC, or CBD ; but, if there be only one angle at a point, it may be **expressed by a letter placed at that point ; as the angle at E.'** VII. When a straight line standing on another straight line makes the adjacent angles equal to one... | |
| John Playfair - Euclid's Elements - 1819 - 333 pages
...therefore the angle ADG is equal (8. 1.) to the angle GDB : Bat 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... | |
| Pierre Simon marquis de Laplace, Thomas Young - Celestial mechanics - 1821 - 388 pages
...described by three letters placed near the lilies, the middle letter at the angular point % 64. DEFINITION. **When a straight line standing on another straight line makes the adjacent angles equal,** they are called right angles. 65. DEFINITION. A straight line between two right angles is called a... | |
| Peter Nicholson - Mathematics - 1825 - 372 pages
...contained by DB. CB, is called the angle DBC, o. CBD j but if thtie be only one angle at a point, it may be **expressed by a letter placed at that point ; as the angle at E.'** 10. When a straight line standing on another straight line makes the adjacent angles equal to one another,... | |
| George Lees - 1826 - 266 pages
...by BD, CB, is called the angle DEC, or CBD ; but, if there be only one angle at a point, it may be **expressed by a letter placed at that point ; as the angle at E.** VII.— When a straight line AB, standing on another straight line CD, makes the adjacent angles ABC... | |
| Robert Simson - Trigonometry - 1827 - 513 pages
...' DB, CB, is called the angle DBC, or CBD ; but, if ' there be only one angle at a point, it may be **expressed ' by a letter placed at that point : as the angle at E.'** X. When a straight line standing on another straight line makes the adjacent angles equal to one another,... | |
| Thomas Curtis - Aeronautics - 1829 - 814 pages
...that form the angle, thus С ü D or D В С denotes the angle contained by the line С В and DB. 7. **When a straight line standing on another straight...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.... | |
| John Playfair - Geometry - 1829 - 186 pages
...contained by Bl), CB, is called the angle DBC1, or CBD. If there be only one angle at a point, it may be **expressed by a letter placed at that point, as -the angle at E.** 10. When a straight line standing on another straight line makes the adjacent angles equal to each... | |
| John Playfair - Euclid's Elements - 1832 - 333 pages
...: therefore the angle 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** /• jii • • i j_ 1 / rr J f* i \ of the angles is a right angle (7. def. 1.) Therefore the aniile... | |
| Thomas Perronet Thompson - Euclid's Elements - 1833 - 150 pages
...equivalent. But whenever the contrary is not expressed, it is always the direct angle that is meant. XXXVII. **When a straight line standing on another straight...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... | |
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