What is the angle between two edges of a cardboard box that meet in a corner?

A good answer might be:

90°


Angles in Three Dimensions

Any two of the three edges of a corner of a cardboard box lie in a plane. The angle between them is 90°.

All the edges of the box intersect at right angles. When the edges are projected to form a 2D picture the angles between the edges are usually not 90°.


 

QUESTION 2:

If your viewpoint changes, do the angles between the edges of the box change?