If the points P, Q, R, S have position vectors āp, āq, ār, ās such that āpāāq=2(āsāār), then find out the correct one:
The diagonal PR of a quadrilateral PQRS bisects the angles P and R, then
If the points P , Q, R and S are collinear points and PQ=RS then prove that PR=QS using Euclid’s postulate.