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
| Euclides - 1853
...8.) 1. The angle AFE is equal to the angle BFE: y -iy 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 (I. Def. 10.) ; therefore 2. Each of the angles AFE, BFE, is a right angle; wherefore... | |
| Euclides - 1855
...Therefore the angle ADG is equal (I. 8) to the angle GD B. But when a straight line standing upon another **straight line makes the adjacent angles equal to one another, each of** these angles is a right angle (I. Def. 10). Therefore the angle GDB is a right angle. But FDB is likewise... | |
| Robert Rawson - 1856
...expressed by a letter placed at that point ; as the angle at E." 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... | |
| W.E. WORTHEN - 1857
...expressed by a letter placed at that point; as the angle at E.' 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 (fig.... | |
| William Ezra Worthen - Mechanical drawing - 1857 - 410 pages
...expressed by a letter placed at that point ; as the angle at E.' When a straight line standing on another **straight line makes the adjacent angles equal to one another, each of the** angles is called a rig fit angle ; and the straight lines are said to be perpendicular to each other... | |
| Elias Loomis - Conic sections - 1858 - 234 pages
...angle ECD is the difference between the two angles BCD, BCE. 10. When a straight line, meeting another **straight line, makes the adjacent angles equal to one another, each of** them is called a right angle, and the straight line which meets the other is called a perpendicular... | |
| Robert Potts - Geometry, Plane - 1860 - 361 pages
...the angle GHC; (I. 8.) and these 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... | |
| Popular educator - 1860
...(I. 4) to the angle CBO ; 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 Schofield Binns - History - 1861
...another, meeting or cutting each other in a point, as c (10) " 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 - History - 1862
...is equal to the angle CHG; (l. 8) 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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