Put the angle you want to convert in this box.
For example, if the angle is 25 degrees, put only 25 in the box.
If the angle is 1P radians, put 1 in the box

Next, choose what you want to convert. degrees to pi radians pi radians to degrees

And click this button.

This is based on the fact that 1P radians = 180^o and 2P radians = 360^o