Answer: Normal vectors.
- A Normal vectors
- B Tangent vectors
- C Lines of intersection
- D Edges
Correct answer: A. Normal vectors
Explanation: The dihedral angle between two planes equals the angle between their normal vectors (or its supplement).
Three mutually perpendicular axes x, y, z meeting at the origin O, with a point P located by its (x, y, z) coordinates.
Concept context
Lines and planes in 3D space, direction cosines, distances, and angles