I have a bit of code that does calculate the angle between 2 faces. The 2 faces share a common edge and they are both oriented correctly.

```
if (edge.faces.length == 2)
angle = edge.faces[0].normal.angle_between(edge.faces[1].normal)
angle = angle.radians
angle = ((angle * 100).round).to_f / 100.0
```

If the angle === 0 then I ignore it - but if there is an angle I want to figure out the inside angle and the corresponding outside angle.

This example returns 20.3 degrees but I’m looking for inside 200.3 degrees and outside 159.7 degrees. The second example has the inside and outside switched.