# Converting VBScript's Atn Function

**Definition**: Returns the arctangent of a number.

### Abs

Granted, this one doesn't come up too terribly often in system administration scripts. Nevertheless, if you ever *do* need to calculate the arctangent of an angle you can do so using the System.Math class and the **Atan** method. This command assigns the arctangent of a 90 degree angle to the variable $a:

```
$a = [math]::atan(90)
```

When you run this command and then echo back the value of $a you should get the following:

```
1.55968567289729
```