Geometry

Question Analysis

This question involves the relationship between two non-parallel planes. The key is to understand the fundamental properties of planes and how they interact when they are not parallel.

Key Concept Explanation:

Parallel planes are defined as planes that do not intersect each other, regardless of how far they are extended. In contrast, intersecting planes meet at a line.

Option Analysis

The correct answer is A. Non-parallel planes share a common line of intersection. When two planes are not parallel, they must intersect. The intersection of two non-parallel planes is a line. This is a fundamental property.

The other options are incorrect:

Option B: Non-parallel planes do not have to be perpendicular; they can intersect at any angle.

Option C: Non-parallel planes must intersect, as non - intersection is a property of parallel planes.

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