 | Richard Dunkley Beasley - Plane trigonometry - 1858 - 144 pages
...or the fraction — - nearly. 66. We must next prove that the angle subtended at the centre of any circle by an arc equal to the radius of the circle is of invariable magnitude. Let A OP (fig. Art. 7) be an angle at the centre of the circle ABA'B', such... | |
 | James Smith - Mathematics - 1865 - 168 pages
...-~i2t == 3456, is the circular measure of an angle of 60°; therefore, 3456 = 57-6, is the value of the angle subtended at the centre of a circle by an arc equal to radius. We obtain the same result in the following way : — 360° x 60 — 2 1 600, = the circumference... | |
 | Isaac Todhunter - Plane trigonometry - 1866 - 206 pages
...that — = 57-29577951... ; this therefore is the number of degrees contained in the angle which is subtended at the centre of a circle by an arc equal to the radius. 212. Thus there are two methods of forming an idea of the magnitude of an angle which is estimated... | |
 | Isaac Todhunter - Plane trigonometry - 1866 - 216 pages
...fraction of four right angles, which is constant, whatever may be the radius of the circle. 210. Since the angle subtended at the centre of a circle by an arc which is equal to the radius is an invariable angle it may be taken as the unit of angular measurement,... | |
 | Hugh Blackburn - Plane trigonometry - 1871 - 132 pages
...numerical value of an angle, it is more suitable and it is usual to represent the angle by its ratio to the angle subtended at the centre of a circle by an arc equal to the radius. This angle (Chap. i. Prop. i. Cor. 2) is invariable, that is, is the same whatever radius be taken,... | |
 | Arthur Rigg - 1873 - 282 pages
...iSs. 4</. each. [Arithmetic. See page 9.] [Specimen Page, No. 5.] 14 ON THE MEASUREMENT OF ANGLES. 28. To shew that the angle subtended at the centre...circle by an arc equal to the radius of the circle if the same for all circles. Let 0 be the centre of a circle, whose radius is r ; AB the arc of a quadrant,... | |
 | Marie Joseph L. Adolphe Thiers - 1873 - 240 pages
...\Arithmctic. See fage 9.] [Specimen Page, No. 5-] 14 ON THE MEASUREMENT OF ANGLES. 28. To shew tJiat the angle subtended at the centre of a circle by an arc equal to the radius of the circle is the lame for all circles. Let 0 be the centre of a circle, whose radius is r ; AB the arc of a quadrant,... | |
 | Braithwaite Arnett - Mathematics - 1873 - 120 pages
...grade, which is the one-hundredth part of a right angle. III. The unit of circular measure, which is the angle subtended at the centre of a circle by an arc equal in length to the radius. DBF. The circular measure of an angle is the number expressing the ratio of... | |
 | Evelyn Abbott - Greek language - 1874 - 224 pages
......... is. each. £1239 . li . 8 = £2. i%s. 4^. each. : Page, No. 5.] 14 ON -THE MEASUREMENT OF ANGLES. 28. To shew that the angle subtended at the centre...circle by an arc equal to the radius of the circle it the same for all circlet. Let 0 be the centre of a circle, whose radius is r ; AB the arc of a quadrant,... | |
 | James Hamblin Smith - Algebra - 1874 - 330 pages
...,£1239 . 11 . 8= £2. 18s. ¿4- each. [Arithmetic. See page 9.] 14 Off THE MEASUREMENT OF ANGLES. 28. To shew that the angle subtended at the centre of a circle by an arc equal to the radius nf the circle is the same for all circles. Let 0 be the centre of a circle, whose radius is r; AB the... | |
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Radian is the angle subtended, at the centre of a circle, by an arc equal in length to the radius... 
