### Definition of Radian

**1.** *Noun.* The unit of plane angle adopted under the Systeme International d'Unites; equal to the angle at the center of a circle subtended by an arc equal in length to the radius (approximately 57.295 degrees).

### Definition of Radian

**1.** *n.* An arc of a circle which is equal to the radius, or the angle measured by such an arc.

### Definition of Radian

**1.** Noun. (geometry) In the International System of Units, the derived unit of plane angular measure of angle equal to the angle subtended at the centre of a circle by an arc of its circumference equal in length to the radius of the circle. Symbol: rad ¹

¹ *Source: wiktionary.com*

### Definition of Radian

**1.** a unit of angular measure [n -S]

### Medical Definition of Radian

**1.**

### Radian Pictures

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### Lexicographical Neighbors of Radian

### Literary usage of Radian

Below you will find example usage of this term as found in modern and/or classical literature:

**1.** *Plane and Spherical Trigonometry* by George Neander Bauer, William Ellsworth Brooke (1917)

"Circular or **radian** measure. A **radian** is an angle of such magnitude that, ...
Thus, if the arc XP is equal to the radius OX, the angle ХОР is a **radian**, ..."**2.** *Plane and Spherical Trigonometry* by Leonard Magruder Passano (1918)

"CHAPTER V THE CIRCULAR OR **radian** MEASURE OF AN ANGLE. INVERSE TRIGONOMETRIC
FUNCTIONS 47. Circular or **radian** Measure of an Angle. Any convenient unit may be ..."**3.** *Plane Trigonometry, for Colleges and Secondary Schools* by Daniel Alexander Murray (1899)

"(1) 1 2 >u 7T B Since all right angles are equal, and since each **radian** is a ...
Ex. With a protractor lay off an angle approximately equal to a **radian**. ..."**4.** *A Course in Electrical Engineering* by Chester Laurens Dawes (1922)

"APPENDIX A Circular Measure—The **radian** The **radian** is circular angle ... The circle
has a radius of r units and •*' the **radian** is subtended by an arc whose ..."**5.** *Elements of Plane and Spherical Trigonometry* by David Andrew Rothrock (1910)

"In this system the unit of measure is the **radian**, the angle subtended at the
center of a circle by an ... 29, the arc BC = ОС, hence the angle COB=I **radian**. ..."**6.** *A First Course in the Differential and Integral Calculus* by William Fogg Osgood (1922)

"**radian** Measure. In Trigonometry, the **radian** measure of an angle was ... Then the
**radian** measure, 6, of the angle is defined as the ratio s/r: ^S' V \9 (1) ..."**7.** *Trigonometry* by Alfred Monroe Kenyon, Louis Ingold (1913)

"**radian** Measure of Angles.* A **radian** is a positive angle such that when its vertex
... Use of **radian** Measure. It is shown in geometry that two angles at the ..."**8.** *Mensuration* by William Shaffer Hall (1893)

"Another unit angle that is often used is called a " **radian**." A **radian** is the
angle at the centre of a circle subtended by an arc equal to the radius. ..."