This video lecture from Vectors (F.Sc.second year Mathematics) covers: Question 2-3 of exercise 7.4. In these questions we find a unit vector perpendicular to the plane containing vector “a” and vector “b”, and also find the sine of angle between them. In question 3 we find the area of triangle determined by three given points. 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.