 | Euclid, Isaac Todhunter - Euclid's Elements - 1867 - 424 pages
...[Definition 24. therefore the angle DCF is equal to the angle ECF; [I. 8. and they are adjacent angles. But when a straight line, standing on another straight...another, each of the angles is called a right angle ; ' [Definition 10. therefore each of the angles DCF, ECF is a right angle. Wherefore/row the given... | |
 | George Frederick Chambers - Astronomy - 1867 - 888 pages
...lines to each other in the same plane gives rise to a plant rectilineal angle, or simply an angle. When a straight line, standing on another straight line, makes the adjacent angles equal to each other, each of those angles is called a right angle; but if the adjacent angles are not equal... | |
 | Robert Potts - 1868 - 434 pages
...(def. 15.) therefore the angle FHC is equal to the angle GHC; (I. 8.) and these 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... | |
 | E. M. Reynolds - Geometry - 1868 - 172 pages
...placed between the other two. When an angle stands alone one letter only is often used, as A. When one straight line standing on another straight line makes...the adjacent angles equal to one another, each of these angles is called a right angle; and the straight line which stands on the other is said to be... | |
 | Isaac Todhunter - Measurement - 1869 - 312 pages
...statement that a certain angle is three times another angle, or four times another angle ; and so on. 8. When a straight line standing on another straight...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. Thus, in the figure,... | |
 | Euclides - 1870 - 270 pages
...360th part of the circumference of a circle, and consequently varies with the size of the 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; and the straight line which stands on the... | |
 | Euclides - 1871 - 136 pages
...the definition. IX. When a straight line (as AS) meeting another straight line (as CD) makes the A adjacent angles equal to one another, each of the angles is called a RIGHT ANGLE; and each line is said to be a PEEPENDICULAB to the other. c X. An OBTUSE ANGLE is one which is greater... | |
 | Hippolyte Taine - Knowledge - 1871 - 606 pages
...each of them perpendicular to a third line, denoting by the name perpendicular the straight line which standing on another straight line makes the adjacent angles equal to one another ; it is from this construction that all the properties of parallels must be deduced. — Now, what... | |
 | 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... | |
 | Euclides - 1877 - 58 pages
...(def. 11) therefore the angle EGC is equal to the angle FGC ; (prop. 8) and they are adjacent angles ; but "when a straight line standing on another straight line makes the adjacent augles equal to one another, the straight line which stands on the other is perpendicular to it." (def.... | |
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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. 
