 | William Ezra Worthen - Architectural drawing - 1857 - 632 pages
...lines, AB, GB, is named the angle ABC, or CBA ; but if there be only one angle at a point, it may be 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,... | |
 | Elias Loomis - Conic sections - 1858 - 256 pages
...the 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... | |
 | Popular educator - 1860 - 536 pages
...equal to the base OH, and the angle CHF (I. 4) to the angle CBO ; 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... | |
 | Robert Potts - Geometry, Plane - 1860 - 380 pages
...together, but are not in the same straight line. NB If there be only one angle at a point, it may be expressed by a letter placed at that point, as the angle at E ; but when several angles are at one point B, either of them is expressed by three letters, of which... | |
 | William Schofield Binns - 1861 - 238 pages
...inclination of two straight lines to one another, meeting or cutting each other in a point, as c (10) " 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... | |
 | Janes Boddely Keene - 1861 - 104 pages
...the angle. Plate I., Fig. 1. 10. Angles are of three kinds. Fig. 2. a. The Right Angle. — If one straight line standing on another straight line makes the adjacent angles equal to one another, each is .called a right angle, and the line standing on the other is said to be perpendicular to it. b.... | |
 | Euclides - 1862 - 140 pages
...two straight lines to one another, which meet together, but are not in the same straight line. 10. 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... | |
 | Euclides - 1862 - 172 pages
...by DB, CB, is called the angle DEC, or CBD ; but, if rhere be only one 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 line makes the adjacent angles equal to one another,... | |
 | Euclides - 1863 - 74 pages
...angle EDC? arc eg, of angle EDO, &c. A degree is the 300th part of the circumference of a circle. 10. When a straight line standing on another, straight line makes the adjacent angles equal to each other, each of these angles is called a right angle; D and the straight line which stands on the... | |
 | Euclides - 1863 - 122 pages
...DB, CB, is called the angle DBC, or C T, T\; but, if there be only one 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 line makes the adjacent angles equal to one... | |
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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. 
