Line-plane parallelism, geometric term. Defined as a line and a plane without a common **** point (not intersecting), is called a line parallel to the plane.

I. Determination:

1. If a line out of the plane is parallel to a line in the plane, then the line is parallel to the plane. This is the decision theorem.

2, if a line has no common *** point with a plane, then the line is parallel to that plane. This method is also called the definitional method.

3, If two planes are parallel, then a line in one of the planes is parallel to the other.

4. If a line outside a plane is parallel to a line parallel to that plane, then that line is parallel to that plane.

5. If a line out of a plane is perpendicular to a line perpendicular to that plane, then that line is parallel to that plane.

Theorem 1: If a line outside the plane is parallel to a line in this plane, then the line is parallel to this plane.

2, Theorem II: a straight line outside the plane is perpendicular to the perpendicular line of this plane, then this line is parallel to this plane.

Relationships between Line Parallel, Line Parallel, and Face Parallel

I. Line Parallel:

1. Two lines are parallel with equal congruent angles: In the same plane, two straight lines are intersected by a third straight line, and if the interior angles of the lines are equal, then these two lines are parallel.

2, the internal error angle is equal to two parallel lines: in the same plane, two straight lines are intercepted by the third line, if the same side of the internal angle complementary, then these two lines are parallel.

3, the same side of the interior angle complementary two lines are parallel.

Two, line parallel:

1, using the definition: to prove that a straight line and the plane has no common **** point.

2, the use of the theorem: from a line parallel to the line to get a line parallel to the plane.

3, the use of the nature of face parallel: two planes are parallel, then a line in one plane must be parallel to the other plane.

Three, face to face parallel:

1, if two planes are perpendicular to the same line, then these two planes are parallel.

2. If two intersecting lines in one plane are parallel to another plane, then the two planes are parallel.

3. If two intersecting lines in one plane are parallel to two intersecting lines in another plane, then the two planes are parallel.