 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.  A course of geometrical drawing - Page 2by William Schofield Binns - 1861Full view - About this book
 | John Clark (drawing master.) - 1840 - 208 pages
...standing on another straight line makes the adjacent angles equal to one another, then the upright une which stands on the other is called a perpendicular to it. The drawing of a perpendicular line is to he thus proceeded with : Suppose the line AB (Fig. 1), which... | |
 | Euclides - Geometry - 1841 - 378 pages
...angle at a point, it may be ' expressed by a le:ter placed at that point; as the ' angle at E." X. When a straight line standing on another straight...stands on the other is called a perpendicular to it. XI. XII. An acute angle is that which is less ^\ than a right angle. X>. XIII. " A term or boundary... | |
 | John Playfair - Euclid's Elements - 1842 - 332 pages
...an* gle at a point, it may be expressed by a letter placed at that point ; as the 'angle at E.' 7. When a straight line standing on another straight...stands on the other, is called a perpendicular to it 8. An obtuse angle is that which is greater than a right angle. 9. An acute angle is that which is... | |
 | Euclides - 1842 - 316 pages
...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...stands on the other is called a perpendicular to it. XI. An obtuse angle is that which is greater than a right angle. XII. An acute angle is that which... | |
 | William Pease - Geometry - 1843 - 80 pages
...that which is formed on the surface of a sphere, by the intersection of two of its great circles. X. When a straight line standing on another straight...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... | |
 | Philip Kelland - Algebra - 1843 - 168 pages
...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... | |
 | Euclides - 1845 - 546 pages
...line standing on another straight line makes the adjacent angles equal to each other, each of these angles is called a right angle ; and the straight...stands on the other is called a perpendicular to it. XI. An obtuse angle is that which is greater than a right angle. XII. An acute angle is that which... | |
 | Euclid, James Thomson - Geometry - 1845 - 382 pages
...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.... | |
 | Scottish school-book assoc - 1845 - 444 pages
...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 which is greater than a right angle. 1 1 . An acute angle is that which... | |
 | Euclid, John Playfair - Euclid's Elements - 1846 - 334 pages
...an1 gle at a point, it may be expressed by a letter placed at that point ; as the ' angle at £.' 7. When a straight line standing on another straight...stands on the other, is called a perpendicular to it. 8. An obtuse angle is that which is greater than a right angle. 9. An acute angle is that which is... | |
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