Question

A plane is a figure. The intersection of two planes that do not coincide (if it exists) is a .

Answer 1

If two planes intersect, they intersect in a line. Two planes that do notintersect are called parallel. Given a plane and a line, there are three possibilities. The line and the plane intersect in a single point.

Answer 2

Two planes may intersect, be parallel, or coincide .

If two planes intersect, then the set of common points is a line that lies in both planes. Two parallel planes can not intersect.

The intersection of two planes that do not coincide (if it exists) is always a line.

If an intersection of the planes  does not exist, the planes are said to be parallel.