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Glite Dictionary
radian

radian

1 8.1
A unit for measuring angles equal to the angle when the circle's edge length equals its radius
  • noun
  • /ˈreɪdiən/
  • Specialized
translation icon : radián
  • To find the angle in radians, you can use the formula: angle in radians equals the length of the arc divided by the radius.
  • degrees or radians
  • radians per second
  • accelerations calibrated in radians

Hi guys, I'm Nancy and this video is about radians and degrees.

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Examples

  • When calculating the circumference of a circle, the angle is measured in radians instead of degrees.

  • These angles are in radians, not degrees.

    NancyPi

  • So grab your calculator and make sure that your calculator is in radians and not degrees because it does not work in degrees.

  • Concept of radian measure: 360 degrees = π radians

    Academic text (1998)

  • Alpha = 90 degrees or π/2 radians.

    Academic text (1997)

  • The motor develops a peak torque of 7.2 oz-in and achieves an acceleration of 78,300 radians per second squared.

    Academic text (1994)

  • In mathematics, a full circle is equal to 2π radians.

Synonyms

rad
vsradian
  • Specialized
4 9.5

A unit for measuring angles equal to about 57 degrees

is the full formal name for the same angle unit

Surface Forms

radian singular
radians plural

Morphology

radian = radius (semi-transparent) = radius + an

Formed from 'radius' + the suffix '-an'; the relation to 'radius' is clear, but the precise mathematical meaning of the unit is specialized and not deducible by general learners.

Etymology

Radian comes from the Latin word radius, which means 'ray' or 'spoke' and is the same root as the common word radius, the line from a circle's center to its edge. A radian is the angle you get when the arc length equals that radius, so the name reminds you that the radius is used to measure the angle.