Tetrahedron with a special angle

What can we state about the angle β when we move the point P?
This activity is linked with a Kahoot quizz, that you can get in [url=https://play.kahoot.it/#/k/85da17b4-936b-4a51-bbff-26a5b18fa60f]https://play.kahoot.it/#/k/85da17b4-936b-4a51-bbff-26a5b18fa60f[/url].

Information: Tetrahedron with a special angle