## Easy as “Pi” Conversion between Degrees and Radians

When working through trig functions in articles such as “How to Constrain Dragging to a Circle,” I often find myself having to convert degrees into radians and vice versa. The formulas are truly simple … but they’re so similar, I often confuse them. For the record:

```
radians = degrees * (pi / 180)
degrees = radians * (180 / pi)
```

However, in a pinch, just use Google. Type, for example, “90 degrees in radians” (without quotes) into the search field and *bingo!* instant conversion.