Select an edge that connects two faces and then use the script below to verify the angle between the two face normals…Try to have face normals like in the example #1 and #2 in the picture above and you will see both puts 90 degrees.

```
model = Sketchup.active_model
selection = model.selection
edges = selection.grep(Sketchup::Edge)
edges.each do |edge|
faces = edge.faces
f1 = faces.first.normal
f2 = faces.last.normal
angle = f1.angle_between f2
angle = angle * 180.0 / Math::PI
puts "angle = #{angle}"
end
```

How can I make example #2 equal 270 degrees while example #1 still be 90 degrees?

Thanks in advance!