The **`tan()`** function returns the tangent of a number in radians. 

The mathematical representation of the `tan()` function is shown below.

>Note:
>- `dart:math` is required for this function.
>- The `tan()` function only works for right-angled triangles. 


#    
## Syntax
```dart
double tan(double num)
```
## Parameter
This function requires a number, `num`, that represents an angle in radians.

In order to convert degrees to radians, use the following formula:
```dart
radians = degrees * ( pi / 180 )
```

## Return value
`tan()` returns the tangent of the number that is sent as a parameter.

## Code


import 'dart:convert';
import 'dart:math';
void main() {
    //positive number in radians
    print("The value of tan(2.3): ${tan(2.3)}");

    // negative number in radians
    print("The value of tan(-2.3): ${tan(-2.3)}");

    //converting the degrees angle into radians and then applying tan()
    // degrees = 45.0
    // PI = 3.14159265
    // result first converts degrees to radians then apply tan
    double result=tan(45.0 * (pi / 180.0));
    print("The value of tan(45.0 * (pi / 180.0)): ${result}");
}

What is tan() in Dart?

Returns the tangent of a number in radians, using dart:math. For right-angled triangles only.