This video lecture from Geometry (F.Sc. second year Mathematics) covers: Question number 7 and 8 of exercise 4.5. In these questions we have to find the joint equation of lines through origin and perpendicular to the given lines. Find more e-learning material and educational video lectures in Urdu at maktab.pk. These videos are free to use for promotional and commercial purpose by keeping the credits to Maktab.