Axiom 2 If two planes have a common point, then they have one and only one common straight line passing through this point.

Axiom 3 passes through three points that are not on the same straight line, and there is only one plane.

Inference 1 passes through a straight line and a point outside this straight line, and there is only one plane.

Inference 2 passes through two intersecting straight lines, and there is only one plane.

Inference 3 passes through two parallel straight lines and there is only one plane.

Determination of plane intersection If two planes have a common point, they are said to intersect.

A straight line outside the judgment plane with parallel lines and planes is parallel to a straight line in this plane, so this straight line is parallel to this plane.

Determination of plane parallelism-If two intersecting lines in a plane are parallel to another plane, then the two planes are parallel. Two planes perpendicular to the same line are parallel.

The essence of parallelism between a straight line and a plane A straight line is parallel to a plane, so any plane passing through this straight line is parallel to the intersection of this plane.

The property that planes are parallel-if two parallel planes intersect with a third plane at the same time, their intersection lines are parallel.

The property of plane parallelism 2 If a straight line is in a plane, the plane parallel to this plane is parallel to this straight line.

If a straight line is perpendicular to two intersecting lines on a plane, it is perpendicular to the plane.

If a line is perpendicular to a plane, a line parallel to the line is perpendicular to the plane. If one plane intersects the perpendicular of the other plane, the two planes are perpendicular.

The nature of vertical line and plane is that two straight lines perpendicular to the same plane are parallel.

The essence of plane verticality When two planes are perpendicular, a straight line perpendicular to the intersection in one plane is perpendicular to the other plane.