 | Robert Simson - Trigonometry - 1762 - 488 pages
...they are adjacent '• angles, but when a ftraight line (landing on a ftraight line makes thee- 8' l' adjacent angles equal to one another, each of them is a right angle, and the ftraight line which (lands upon the other is called a perpendicular to it. therefore from the given... | |
 | Robert Simson - Trigonometry - 1775 - 534 pages
...to the angle CHG; and they are adjacent angles ; but when a ftraight line ftanding cet on a ftraight line makes the adjacent angles equal to one another, each of them is a right angle, and the ftraight line which flands upon the other is called a perpendicular to it; therefore from the given... | |
 | Robert Simson - Trigonometry - 1781 - 534 pages
...the angle CHG; and they are adjacentc. 8. i. angles. but when a ftraight line ftanding on a ftraight line makes the adjacent angles equal to one another, each of them is aright angle, and the ftraight linewhich ftands upon the other is called a perpendiculartoit. therefore... | |
 | John McGregor (teacher of mathematics.) - Mathematics - 1792 - 532 pages
...two, thus : ABC, or СВЛ. 11. When one ftraight line falls upon another ftraight line, fo as to make the adjacent angles equal to one another, each of them is a right angle and the ftraight Une which falls upon the other is perpendicular to it. See plate i.fg- 4. I г. An angle which... | |
 | Euclid, John Playfair - Euclid's Elements - 1795 - 462 pages
...the angle AFE is equal b to the angle BFE : But when a flraight line ftanding upon another nv.ik.es the adjacent angles equal to one another, each of them is a right c angle: Therefore each of the angles AFE, Bl' E is a right angle ; wherefore the ftraight line CD,... | |
 | Alexander Ingram - Trigonometry - 1799 - 374 pages
...to the angle , CHG ; and they are adjacent angles ; but when a ftraight line ftanding on a ftraight line makes the adjacent angles equal to one another, each of them is a right angle, and the ftraight line which ftands upon the other, is called a perpendicular to it ; therefore from the given... | |
 | Robert Simson - Trigonometry - 1804 - 530 pages
...angle CHG; and they are adjacent e. 8. i. :angles. but when a ftraight line flanding on a ftraight line makes the adjacent angles equal to one another, each of them is a right angle, and the ftraight line which ftands upon the other is called af perpen- f. to.Def.t. dicular to it. thereforefrom... | |
 | John Playfair, Euclid - Circle-squaring - 1804 - 468 pages
...therefore the angle AFE is equal b to the angle BFE. And when a ftraight line flanding upon another makes the adjacent angles equal to one another, each of them is a right c angle : Therefore each of the angles AFE, BFE is a right angle; wherefore the ftraight line CD, drawn... | |
 | John Playfair - Mathematics - 1806 - 320 pages
...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 another, each of the angles is called a right angle ; and the straight line which stands on the other is called a perpendicular... | |
 | Robert Simson - Trigonometry - 1806 - 546 pages
...G * : therefore the angle ADG is equal c 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 d : therefore the angle GDB is a right angle: but FDB is likewise a '"... | |
| |
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. 
