दो गैर-शून्य (non-zero) सदिशों का अदिश गुणनफल (scalar product) शून्य होगा, यदि और केवल यदि दोनों सदिशों के बीच का कोण हो:

If iî, jî and kî are the three unit vectors along the x-direction, y-direction and z-direction, respectively, what will be the magnitude of the vector (iî - jî)?

Two vectors P⃗ and Q⃗ have equal magnitudes. If the magnitude of (P⃗ + Q⃗) is n times the magnitude of (P⃗ - Q⃗), then the angle θ between P⃗ and Q⃗ is given by: