radian
Sign in to saveThe radian, denoted by the symbol rad, is the unit of angle in the International System of Units (SI) and is the standard unit of angular measure used in many areas of mathematics. It is defined such that one radian is the angle subtended at the center of a plane circle by an arc that is equal in length to the radius. The unit is defined in the SI as the coherent unit for plane angle, as well as for phase angle. Angles without explicitly specified units are generally assumed to be measured in radians, especially in mathematical writing.
AI overview
A radian is the standard unit for measuring angles in mathematics and the International System of Units, defined as the angle created at the center of a circle when an arc length equals the radius of that circle. Radians matter because they're the default unit for angles in mathematical work, making calculations and formulas simpler and more consistent across science and engineering.
AI-generated from the Wikipedia summary — may contain errors.
Key facts
- Unit.standard
- SI
- Unit.name
- Radian
- Unit.image
- Circle radians.gif
- Unit.caption
- An arc of a circle with the same length as the radius of that circle subtends an angle of 1 radian. The circumference subtends an angle of 2 radians.
- Unit.quantity
- angle
- Unit.symbol
- rad
- Unit.units1
- milliradians
- Unit.inunits1
- 1000 mrad
- Unit.units2
- turns
- Unit.inunits2
- turn ≈ 0.159154 turn
- Unit.units3
- degrees
- Unit.inunits3
- ° ≈ 57.295779513°
Article
17 sectionsContents
- Definition
- Unit symbol
- Dimensional analysis
- Conversions
- Between degrees
- Between gradians
- Usage
- Mathematics
- Physics
- Prefixes and variants
- History
- Pre-20th century
- As an SI unit
- See also
- Notes
- References
- External links
The radian, denoted by the symbol rad, is the unit of angle in the International System of Units (SI) and is the standard unit of angular measure used in many areas of mathematics. It is defined such that one radian is the angle subtended at the center of a plane circle by an arc that is equal in length to the radius. The unit is defined in the SI as the coherent unit for plane angle, as well as for phase angle. Angles without explicitly specified units are generally assumed to be measured in radians, especially in mathematical writing.
== Definition ==