A bug displaying an Angle in 3D view?
I am pretty sure this is a bug, but as I am quite new with Geogebra, I am not sure of it.
May be it is a misunderstanding in my side about how Geogebra mesuares angle.
In this construction, the angle alpha_m is not displayed correctly in 3D view.
It seems that the angle is correctly calculated, and correctly drawn in the 2D view (xOy Plane).
But in 3D it is drawn incorrectly.
The angle is measured in the 2D plane, and defined as the angle formed by 3 points, V_P (the projection of V over the XY plane), the origin and a point in the Y axis (0,1).
In 3D the angle seems to be drawn as the one forme with the X axis.
I attach the construction.