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
| Jeremiah Day - Mathematics - 1836 - 472 pages
...which meet together but are not in the same straight line. 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... | |
| Euclid - Mathematics - 1837 - 390 pages
...straight lines meet is called the vertex of the angle. 8. 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 - Trigonometry - 1838 - 416 pages
...is equal (8. 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... | |
| Euclides - History - 1838
...by a letter 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 of the** angles is called a right angle ; and the straight lines are said to be perpendicular to each other.... | |
| Euclides - 1841
...angle AFE is equal* to the angle BFE: /^~ ^X^ * 3. 1. but when a straight line, standing upon another **straight line, makes the adjacent angles e.qual to one another, each of** them is a right* angle: therefore each of the angles AFE, BFE is a right angle; wherefore the straight... | |
| John Playfair - Mathematics - 1842 - 317 pages
...is equal (8. 1.) to the angle CHG ; and they 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... | |
| Euclides - History - 1842
...1.) to the angle c н G ; and they are adjacent angles : but when a straight line standing on another **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... | |
| William Pease - Geometry - 1843 - 68 pages
...sphere, by the 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 of the** angles is called a right angle ; and the straight line which stands on the other is called a perpendicular... | |
| Euclides - Geometry - 1845 - 199 pages
...equal § II is Def. 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... | |
| Scottish school-book assoc - History - 1845
...it may be 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... | |
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