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. Elements of Geometry and Conic Sections - Page 10by Elias Loomis - 1849 - 226 pagesFull view - About this book
| Isaac Todhunter - Measurement - 1869 - 312 pages
...three times another angle, or four times another angle ; and so on. 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... | |
| Elias Loomis - Geometry - 1871 - 302 pages
...divided. Thus, the angle BCD is the sum of the two angles BCE, ECD ; and the angle ECD is the difiei ence between the two angles BCD, BCE. 10. When a straight...perpendicular to it. 11. An acute angle is one which is lew than a right angle. An obtuse angle is one which .'s greater than a right angle. 12. Parallel straight... | |
| Alfred Hiley - 1871 - 184 pages
...sides AB, AC, but upon the extent or opening between the lines. XI. When a straight line standing upon another straight line makes the adjacent angles equal to one another, each of them is called a right A angle ; and the straight line standing upon the other is called a perpendicular to it. Thus if AB,... | |
| William Alexander Myers - Circle-squaring - 1873 - 238 pages
...concentric circles ; *that is, having a common center, as at F. 14. When a straight line standing on another straight line makes the adjacent angles equal to one another, each of the angles is a right angle, and the straight line which stands on the other is called a perpendicular... | |
| Henry Major - Student teachers - 1873 - 580 pages
...line. An angle is named from three or one letters, as ABC or B. X. When a straight line standing oil 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... | |
| Francis Cuthbertson - Euclid's Elements - 1874 - 400 pages
...respects, and.-. AE is =BE; (i. i) ( 14 ) RIGHT ANGLES. DEFINITION. When one straight line, standing on another straight line, makes the adjacent angles equal...called a right angle; and the straight line which stands upon the other is said to be perpendicular to it. PROPOSITION VI. If two straight lines cut... | |
| John Clement P. Aldous - Trigonometry - 1874 - 104 pages
...There is one well-known angle by which angles may be measured. DBF. When one straight line standing on another straight line makes the adjacent angles equal to one another, each of these angles is called a Bight Angle. Now all right angles are equal to one another. So that any angle... | |
| Euclides - 1874 - 120 pages
...equal to the angle CHG [I. 8.] ; 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 the angles is called a right angle, and the 'straight line which stands on the other is called a perpendicular... | |
| Euclides - 1874 - 342 pages
...therefore 1. The cmgle ADG is equal to the angle GDB (I. 8), 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 (I. Def. 10) ; therefore 2. The angle GDB is a right angle ; but FDB is... | |
| William Alexander Myers - Circle-squaring - 1874 - 207 pages
...concentric circles ; that is, having a common center, as at F. 14. When a straight line standing on another straight line makes the adjacent angles equal to one another, each of the angles is a right angle, and the straight line which stands on the other is called a perpendicular... | |
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