 | Alfred Hiley - 1879 - 228 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... | |
 | Isaac Sharpless - Geometry - 1879 - 282 pages
...and CF common, therefore (I.4) the angles DCF, ECF, opposite the equal sides, are equal. But when a straight line standing on another straight line makes the adjacent angles equal to each other, each of them is a right angle. (Def. 8.) Therefore CF is at right angles to AB. ANALYSIS.... | |
 | Isaac Todhunter - Euclid's Elements - 1880 - 426 pages
...centre G ; [I. Definition 15. therefore the angle ADG is equal to the angle BDG. [I. 8. But when a straight line, standing on another straight line,...the adjacent angles equal to one another, each of the angles is called a right angle ; [I. Definition 10. therefore the angle BDG is a right angle. But... | |
 | T S. Taylor - 1880 - 150 pages
...being an equilateral triangle). (/) .-. the angle DCF is equal to the angle ECF. and Syllogism. When a straight line, standing on another straight line, makes the adjacent angles equal, each of the angles is called a right angle (Euc. Def. 10). The straight line FC standing on the straight... | |
 | Euclides - Euclid's Elements - 1881 - 236 pages
...inverted commas, as being Dr. Simson's addition ; it is very necessary to be remembered. X. When a straight line standing on another straight line makes...of these angles is called a right angle ; and the straignt line which stands on '..he other is called a perpendicular to it. By borrowing the terms vertical... | |
 | William Schofield Binns - 1881 - 214 pages
...straight lines to one another, meeting or cutting each other in a point, as (10) "When a straight lino 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... | |
 | George Albert Wentworth - 1881 - 266 pages
...Thus if the straight line AB meet the straight line С D so that the adjacent angles ABC and AB D are equal to one another, each of these angles is called a right angle. 26. DEF. Perpendicular Lines are lines which make a right angle with each other. 27. DEF. An Acute... | |
 | Marianne Nops - 1882 - 278 pages
...right angle, called acute (Lat. acutus, sharp). These are thus defined by Euclid : — 10. ' 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... | |
 | 1883 - 248 pages
...same point. This point is called the vertex of the angle. When one straight line standing on another makes the adjacent angles equal to one another, each of these angles is called a riylit angle. A triangle is a figure contained by three straight lines. A rectangle is a quadrilateral... | |
 | John Ogilvie - 1882 - 724 pages
...as AB (flg. 3), standing ou another straight line c D, makes the two Kg- 5Fig. 4. angles ABC and ABD equal to one another, each of these angles is called a right angle. An acute angle is that which is less than a right angle, as EB c. An obtum angle Is that which is greater... | |
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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. 
