The length of the radius is marked off along the circumference, and another radius is marked off at its end. The resulting angle (in red) is equal to one radian.

In geometry and algebra, a radian is an angle measurement on a circle, though, instead of using degrees, the length of the circle's radius is used to measure angles.

One radian is approximately 60°.

Conversions[edit | edit source]

Degrees to Radians[edit | edit source]

To convert from degrees to radians, multiply d degrees by π÷180.

E.g.

60° is equal to radians.

Radians to Degrees[edit | edit source]

To convert from radians to degrees, multiply r radians by 180÷π.

E.g.

How Many Radians is a Circle?[edit | edit source]

We know that a circle is 360°. Using our conversion methods to convert degrees into radians, we can figure this out.

Therefore, 360° is equal to 2π radians.

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