Wikipedia:Reference desk/Archives/Mathematics/2018 November 6

= November 6 =

Angles in 4D space
3D space has 2 kinds of angles; dihedral and polyhedral. Dihedral angles are related to edges. Polyhedral angles are related to vertexes. But how about the kinds of angles in 4D space?? Georgia guy (talk) 01:34, 6 November 2018 (UTC)


 * You might want to check out Solid angle. Really, I think you'd say that 3D only has one kind of angle: solid angle.  The angles between two vectors on the other hand (which I guess is what you're referring to as dihedral) is really just a normal 2D angle – those 2 vectors determine a plane, and the normal notion of 2D angle can be considered in that plane.  Likewise, in 4D, you can have an angle between 2 vectors (in a plane determined by those vectors), but you can also have a 3D solid angle (in a figure that sits in a 3D subspace), or the full analog of 4D solid angle.  And so on in higher dimensions.  –Deacon Vorbis (carbon &bull; videos) 01:51, 6 November 2018 (UTC)