## Dart program to convert degree to radian and vice versa:

This program will show you how to convert a value in *degree* to *radian* and vice versa. *360°* is equal to *2π* radians. So, *1°* is equal to *2π/360* radian or *0.0174533* radian. Similarly, *1* radian is equal to *360/2π* degree.

For *raidan*, *degree* conversion, we can write our own methods or we can use a third party library to do that. In this post, I will show you both of these ways.

### Write own function to convert degree to radian and vice versa:

Let’s take a look at the below program:

```
double PI = 3.141592653589793238;
double degreeToRadian(double degree) {
return degree * PI / 180;
}
double radianToDegree(double radian) {
return radian * 180 / PI;
}
void main() {
List<double> radianValues = [0, 1, 5, 10, 20];
List<double> degreeValues = [0, 57.29577951308232, 90, 360];
for (double radian in radianValues) {
print("$radian Radian = ${radianToDegree(radian)} Degree");
}
for (double degree in degreeValues) {
print("$degree Degree = ${degreeToRadian(degree)} Radian");
}
}
```

Here,

*PI*is a*double*variable to hold the value of*π*.*degreeToRadian*method is used to convert one*degree*value to*radian*. It returns the result in*double*.*radianToDegree*is used convert one*radian*value to*degree*.*radianValues*is a list of values in*radian*we wants to convert to*degree*. Similarly,*degreeValues*is a list of values in*degree*that we will convert to*radian*.- Using two
*for-in*loops, we are converting all*radian*values to*degree*and all*degree*values to*radian*. The*print*statements are used to print these values to the user.

### Output:

This program will print the below output:

```
0.0 Radian = 0.0 Degree
1.0 Radian = 57.29577951308232 Degree
5.0 Radian = 286.4788975654116 Degree
10.0 Radian = 572.9577951308232 Degree
20.0 Radian = 1145.9155902616465 Degree
0.0 Degree = 0.0 Radian
57.29577951308232 Degree = 1.0 Radian
90.0 Degree = 1.5707963267948966 Radian
360.0 Degree = 6.283185307179586 Radian
```

## Using vector_math library:

*vector_math* library provides different properties and methods for degree to radian conversion. This is a third party library. Use the below in your *pubspec.yaml* file:

```
dependencies:
vector_math: any
```

Run *pub get* to install the library.

Use the below import to import the library:

`import 'package:vector_math/vector_math.dart';`

We can use the below constants:

`degrees2Radians → const double`

It converts an angle from degree to radian. And:

`radians2Degrees → const double`

It gives degree value from radian.

We can also use the below method:

`degrees(double radians) → double`

and:

`radians(double degrees) → double`

Both of these methods takes one *double* value and returns the required *double* value.