 | John Ward - Mathematics - 1747 - 492 pages
...is, AC, and C J5, are Perpendicular to £> C, as well as -D, C is to /•j'r/W or both of them. g. An OBTUSE ANGLE is that which is greater than a Right Angle. Such is the Angle included between the Lines AC and n CB. 10. An ACUTE ANGLE is that ^_ which is lefs... | |
 | Proclus (Diadochus.) - 1788 - 350 pages
...and the infifting Right Line, is called a PERPENDICULAR to that upon which it ftands. DEFINITION Xf. An OBTUSE ANGLE is that which is greater than a RIGHT ANGLE. DEFINITION XII. But an ACUTE ANGLE, is that which is Icfs than a RIGHT ANGLE, THESE are the triple... | |
 | David Steel - 1805 - 392 pages
...each other. When a straight line AD standing upon another CB, makes angles ADC, ADB, on each side, equal to one another; each of these angles is called a Right Angle; and C J> B the line AD is said to be Perpendicular to the line CB. An angle is usually expressed by three... | |
 | John Playfair - Mathematics - 1806 - 320 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...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... | |
 | Robert Simson - Trigonometry - 1806 - 546 pages
...G * : therefore the angle ADG is equal c 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: but FDB is likewise a '"... | |
 | Charles Vyse - Arithmetic - 1806 - 342 pages
...placed at the Angular Point being always wrote in the Middle, as ADC (Fig. 4. denotes the Angle I. An Obtuse Angle is that which is greater than a right Angle, as CAB, (Fig 3.; An acute Angle is that which is less than a right Angle, »s DCB, (Fig. 4.) A Superficies... | |
 | Euclid - Geometry - 1810 - 554 pages
...equal e to the angle CHG; and 1. they are adjacent angles; but when a straight line standing on ae 8. 1 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... | |
 | John Mason Good - 1813 - 714 pages
...two straight lines to or.e 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... | |
 | George Adams - Geometry - 1813 - 576 pages
...straight line AB, //<>-. 1 , plate 4, standing upon another CD, makes angles ABC, ABD, on each side equal to one another ; each of these angles is called a right angle ; and the line AB is said to be perpendicular to the line CD. It is usual to express an angle by three letters,... | |
 | George Adams - Geometry - 1813 - 648 pages
...in the middle ; as B is the angle of AB C. An acute angle is that which is less than a right angle. An obtuse angle is that which is greater than a right angle. A line AB, Jig. 2, plate 4, cutting another line CD in E, will make the opposite angles equal, namely,... | |
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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. 
