# Geometry question (not homework)

## Main Question or Discussion Point

can planes only rise up or dip down like this?

/ Plane B
/
/
/
/

_____________________________ Plane A

or can Plane B intersect A like this?
_____________________________________
|BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB|
|BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB|
|BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB|
|BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB|
|BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB|
|BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB|
|_____________________________________|___ Plane A
|BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB|
|_____________________________________|

bad drawing but i dont know any other way.

If your drawing is referring to planes intersecting at right angles, the most apparent example is the intersection of the xy-plane with the xz-plane.

We had a problem in class that said that through a given line on plane A there is only one plane that intersects plane B (not dealing with my pictures). I thought there would be an infinite amount of planes.

HallsofIvy
Homework Helper
Someone502 said:
We had a problem in class that said that through a given line on plane A there is only one plane that intersects plane B (not dealing with my pictures). I thought there would be an infinite amount of planes.
Was there more to the problem? Imagine rotating the plane around the line where it intersects A. That will give an infinite number of planes that still intersect B.

my teacher said that there was only one and thats what im asking about.

opps and the plane that intersects plane B pass through the line.

Are you sure he didn't say any two given planes can only intersect once? because that would make alot more sense.

no pretty sure

Well there should be infinite planes (B) that intersect with A. Just think about it. In fact, only planes which are parallel to each other won't intersect.

ok my teacher said there was only one and i thought he was wrong but wasnt sure