The intersection of two planes forms the plane angle How many parts of the space are the three planes that do not coincide with each other? Some say 8, some say 7, and 8

The intersection of two planes forms the plane angle How many parts of the space are the three planes that do not coincide with each other? Some say 8, some say 7, and 8

The intersection of two planes forms the plane angle
Three planes that do not coincide with each other divide the space into eight parts at most
Imagine the space is a piece of tofu, first vertical cross cut two knives
Cut out four pieces, right
Then, the waist is cut in half horizontally, isn't it 8 pieces?

What's wrong with "dihedral angle is a figure formed by the intersection of two planes"?
HELP ME.
Kannst du mir helfen?

The figure formed by two half planes is called dihedral angle;
Two planes intersect to form four dihedral angles, so it's wrong

If two planes are perpendicular to each other, the dihedral angle formed by the two planes is a straight dihedral angle

That's right

If θ is the plane angle of dihedral angle, then the range of θ is?

(0,π)