Two walls or a wall and floor of a room intersecting.
Yes, two planes have intersected.
wateva
Think you just answered your own question. A plane is a line. Two planes= two lines.
A dihedral angle is the angle between two intersecting planes.
Two walls or a wall and floor of a room intersecting.
Not really. A railroad intersection would be an example of two lines intersecting. An example of two planes intersecting would be the ground and the side of a building or the ground and the railroad crossing sign post.
Yes, two planes have intersected.
Two lines in two intersecting planes can be parallel, intersecting, or skew.
The corner of a room is the intersection of two adjacent walls.
yes
A line, or intersecting planes.
Intersecting planes!
One.
wateva
Yes. Assuming it's a relatively standard shelf and wall.
A line. Unless the two planes are the same, in that case a plane.