Another way to represent an angle is by using **radians**. Without getting too technical, a **radian** is defined as the angle between 2 radii (plural for radius) of a circle where the arc between them has length of one radius.

While it’s not stated in the animation, the **arc length** equals the length of one radius when the angle is approximately 57.2958°. This leads us to two new conversion ratios:

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Extending this notion further:

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We can use any of these conversion ratios to convert between radians and degrees. Let’s watch three examples:

Now you might run into a situation where you’ll be expected to convert an angle in radians to degrees, minutes, seconds – which was covered extensively in the previous lesson. To make this conversion, you’ll need the conversion ratios introduced above along with ones stated below:

- 1 minute (‘) is equal to 1/60 of a degree.
- 1 second (”) is equal to 1/3600 of a degree.

A video demonstration is shown below:

- Keep in mind that the answer provided doesn’t take into account significant figures.