| John Playfair - Geometry - 1829 - 210 pages
...one angle at a point, it may be expressed by a letter placed at that point, as -the angle at E. 10. When a straight line standing on another straight line makes the adjacent angles equal to each other, each of the angles is called a right angle; and the straight line which stands on the other... | |
| James Charlton - Geography - 1829 - 250 pages
....,; . l 5tn"A f itei,*& i theinc!ination or opening -of two angles is called a RIGHT ANGLE ; and the line which stands on the other, is called a PERPENDICULAR to it. •• • > i •••••• i OF THE TERRESTRIAL •'CLdME.'"' 28. The TERRESTRIAL GLOBE is an... | |
| John Playfair - Euclid's Elements - 1832 - 358 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 /• jii • • i j_ 1 / rr J f* i \ of the angles is a right angle (7. def. 1.) Therefore the aniile... | |
| Euclid - Euclid's Elements - 1833 - 216 pages
...(ABC and ABD) equal to one another, each of these angles is called a right angle ; B and the right line, which stands on the other, is called a perpendicular to it. Fig. 1. 12. The angle (ABC), which is greater than a right angle, is called obtuse. Fig. 4. 13. The... | |
| Euclides - 1834 - 518 pages
...the base CG: therefore the angle CHF is equal* to the angle CHG ; and they are adjacent angles: but when a straight line, standing on another straight...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... | |
| Mathematics - 1835 - 684 pages
...letter, as A, 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... | |
| Euclid - 1835 - 540 pages
...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... | |
| Mathematics - 1836 - 488 pages
...of two straight lines to one another, which meet together but are not in the same straight line. 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... | |
| John Playfair - Euclid's Elements - 1836 - 488 pages
...angle at a point, it may be expressed by a letter placed ' at that point ; as the angle at E.' VII. When a straight line standing on another straight line makes the adjacent angles equal to one an, other, each of the angles is called a right angle; and the straight line which stands on the other... | |
| John Playfair - Geometry - 1836 - 148 pages
...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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