A plane is an undefined term because it
A:can be named using three noncollinear points.
B:is described generally, not using a formal definition.
C:is where other geometric shapes can be constructed.
D:is a flat surface that extends indefinitely in all directions.

Question

A plane is an undefined term because it
A:can be named using three noncollinear points.
B:is described generally, not using a formal definition.
C:is where other geometric shapes can be constructed.
D:is a flat surface that extends indefinitely in all directions.

directrix · Answer

In Euclidean Geometry, there are three undefined terms.  As the post states, plane is one of them. There is no formal definition.

@raybrant416