**Radian** refers to a unit of angle known as the arc degree method. It was introduced in the second year in high school along with the trigonometric functions. It is used primarily in mathematics and physics.

This page will explain the meaning of Radians and how you can convert them into degrees in degrees.

## Radian: What does it mean?

**Definition for radian**

**The radian**, which is the unit of plane angles of the International System of Units(SI), is defined as:

1 Radian refers to the magnitude of the central angle of an arc equal in length to the radius of the circle.

The unit symbol is **rad**. The expression of the angle that is used with this unit is called **radian method**.

Even so, it is difficult to capture an image by simply listening to it one time. Let’s use figures to understand the definition.

The figure below shows an orange line that represents an arc that has a length equal the radius of the circle. **1radian** is the magnitude of this arc’s central angle (orange corner).1 radian diagram(1 radian57.2958deg)

The next section will explain how to convert one radian into “degrees” (deg). This gives us a fraction of 57.2958deg. This value actually has an infinite number decimals.

This was a problem! It may seem difficult to express an angle using this method, but don’t be discouraged. Although the degree method can sometimes use 1 deg ,…,, it is not likely that radians will be separated by integer values like 1 rad ,….. The **angle** is represented by the basic p for radians.

Next, I’ll explain how to convert between “radians” and “degrees”.

By the way, **Radians** are frequently **without the unit rad**. Because the radians are “the proportion of the length arc to the radius”, which is “the length divided with the length”, the units cancel one another.

## Radians: How to Use

Radians are not a good idea, as they only give the ratio of r and x to the angle calculated using trigonometric function.

It is used to approximate angles linearly (simplification and acceleration of calculations), but its meaning as radians is unclear.

When **differentiation** takes place, Radians are at their best.

Trigonometric functions in differentiation are not supported by ” **degrees**” and ” **Radians**“.

When explaining trigonometric functions, the true meaning of radians is revealed.

**The angle value input to trigonometric function** **radians**. Not only are trigonometric functions in radians in C language, but also in Excel. The exception is Unity in the game engine. However, Unity is expressed in degrees. Because the program was written in C #, and Math is used to calculate, the program is treated in units in radians at the end. There are many reasons it is radian for trigonometric functions, but the main reason is series expansion (polynomial approach) which is used to get highly accurate calculations.

To be able to use trigonometric functions, you don’t need to know differentiation or series expansion. To fully understand trigonometric function, you must first understand differentiation. Series expansion is also necessary in order to understand internal processes. However, when working with trigonometric functions, it suffices that the **degrees** are converted into **radians**.