Answer: Perpendicular.
- A Parallel
- B Perpendicular
- C Equal
- D Anti-parallel
Correct answer: B. Perpendicular
Explanation: a.b = |a||b|cos(theta) = 0 implies cos(theta) = 0, so theta = 90 degrees. The vectors are perpendicular.
Triangle law of vector addition: placing vector b at the head of vector a, the diagonal from the start to the final head gives the resultant a + b.
Concept context
Vectors, dot product, cross product, and geometric applications