When a straight line set up on a straight line makes the adjacent angles equal to one another, each of the equal angles is right, and the straight line standing on the other is called a perpendicular to that on which it stands. Introduction and books 1,2 - Page 181by Euclid, Sir Thomas Little Heath, Johan Ludvig Heiberg - 1908Full view - About this book
| John Playfair - Trigonometry - 1819 - 333 pages
...is equal (8. 1.) to the angle CHG ; and thpy are adjacent angles ; now when a straight line standing **on a straight line makes the adjacent angles equal to one another, each of** them is a right angle, and the straight line which stands upon the other is called a perpendicular... | |
| Peter Nicholson - Mathematics - 1825 - 372 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 of the** angles is a right angle : (Ю. Def. 1 .) Therefore the angle GDB is a right angle. But FDB is likewise... | |
| Euclides - 1826
...are right lines, it is called a rectilineal angle. 10. When a right line standing on another right **line, makes the adjacent angles equal to one another, each of the equal angles is** a right angle, and the right Tine standing on the other is called a perpendicular. 11. An obtuse angle... | |
| Euclid, Phillips - 1826 - 180 pages
...are right lines, it is called a rectilineal angle. 10. When a right line standing on another right **line, makes the adjacent angles equal to one another, each of the equal angles is** a right angle, and the right line standing on the other is called a perpendicular. 11. An obtuse angle... | |
| Robert Simson - Trigonometry - 1827 - 513 pages
...therefore the angle AFE is equal * to the angle BFE: but when a straight line standing upon another **straight line makes the adjacent angles equal to one another, each of** them is a right* angle; therefore each of the angles AFE, BFE, *1oDef. 1. is a right angle: wherefore... | |
| Thomas Curtis - Encyclopedias and dictionaries - 1829
...С denotes the angle contained by the line С В and DB. 7. 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.... | |
| Thomas Perronet Thompson - Euclid's Elements - 1833 - 150 pages
...expressed, it is always the direct angle that is meant. XXXVII. 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... | |
| Euclid, Robert Simson - Geometry - 1835 - 513 pages
...angle CHF is equal" to the angle CHG ; and they are adjacent angles ; but when a straight line standing **on a straight line makes the adjacent angles equal to one another, each of** them is a right angle ; and the straight line which stands upon the other is called a perpendicular... | |
| Society for the diffusion of useful knowledge (Great Britain) - Mathematics - 1835
...always denotes the angular point. 10. (Eue. i. det 10.) When a straight line standing; upon another **straight line makes the adjacent angles equal to one another, each of** them is called a right angle, and the straight line which stands upon the other is called a perpendicular... | |
| John Playfair - Geometry - 1836 - 114 pages
...is equal (7. 1.) to the angle CHG, and they are adjacent angles ; but when a straight line, standing **on a straight line, makes the adjacent angles equal to one another, each of** them is a right angle, and the straight line which stands upon the other, is called a perpendicular... | |
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