Hi Willy, there are 2 things to consider:

First, the angle the method returns is in radians, so youâ€™ll need to convert it to degrees.

Second, if you do not provide a proper plane, it can be that youâ€™ll get the reflex angle, which you have to subtract from 180 degrees. This seems to be the case here, `2.059`

in radians equals `117.97201`

degrees, once you subtract it from `180`

youâ€™ll get `62.0279`

degrees.

Youâ€™ll might also try to use the method which allows to define a plane. Using a plane normal as a third vector technically allows to get a signed angle. The math behind should be something like below function, which is python btw:

```
def GetSignedAngle(Va, Vb, Vn):
'''gets signed angle between Va and Vb, Vn is the plane normal'''
# all vectors must be unitized
cross = Rhino.Geometry.Vector3d.CrossProduct(Va, Vb)
# angle in radians
return math.atan2(cross * Vn, Va * Vb)
```

_

c.