 | Euclides - 1814 - 560 pages
...one angle at a point, it may be ex' pressed by a letter placed at that point; as the angle at E.' X. When a straight line standing on another straight...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... | |
 | John Gummere - Surveying - 1814 - 398 pages
...perpendicular to AB, Fig. 4. 10. An acute angle is that which is less than a right angle, as BDE, Fig. 4. 11. An obtuse angle is that which is greater than a right angle, as ADE, Fig. 4. 13. Parallel straight lines are such as are in the same plane, and which, being produced... | |
 | Charles Vyse - Arithmetic - 1815 - 340 pages
...placed at the angular point being always wrote in the middle, as A DC (Fig. 4.) denotes the angle b. An obtuse angle is that which is greater than a right angle, as CAB (Fig. 3.). An acute angle is that which is Iess than a right angle, as DCB(Fig.4.). Parallel... | |
 | Euclides - 1816 - 588 pages
...centre G*: Therefore the angle ADG is equal0 to the angle GDB : 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 d: Therefore the angle GDB is a right angle: MoDef. ' But FDB is likewise... | |
 | Encyclopaedia Perthensis - 1816 - 772 pages
...RIGHT Ax OLE and the ftraight line which (lands on the other ii called a PERPENDICULAR. Fig. 4. 8. An OBTUSE ANGLE is that which is greater than a right angle. Fig. 5. 9. An ACUTE ANGLE is that which is left than a right angle. F,:g. 6. 10. PARALLEL STRAIGHT... | |
 | John Playfair - 1819 - 354 pages
...one 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...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... | |
 | John Playfair - Circle-squaring - 1819 - 350 pages
...therefore the angle ADG is equal (8. 1.) to the angle GDB : Bat 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 (7. def. 1.). Therefore the angle GDB is a right angle: But FDB is likewise... | |
 | John Mason Good - 1819 - 800 pages
...adjacent angles equal to one another, each of (lie angles is called и right angle; and the ira glu line which stands on the other is called a perpendicular to it. 11. An obtuse angle is that which is g cater than a right an^le. 12. Ли acute angle is that which... | |
 | Euclid, Robert Simson - Geometry - 1821 - 514 pages
...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. XI. An obtuse angle is that which is greater than a right angle. XII. An acute angle... | |
 | Pierre Simon marquis de Laplace, Thomas Young - Capillarity - 1821 - 402 pages
...described by three letters placed near the lilies, the middle letter at the angular point % 64. DEFINITION. When a straight line standing on another straight line makes the adjacent angles equal, they are called right angles. 65. DEFINITION. A straight line between two right angles is called a... | |
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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. 
