This video lecture from Geometry (F.Sc.second year Mathematics) covers: Question number 8 and 10 of exercise 4.1. Question 8 helps us find the centre and radius of a circle when the coordinates of end points of the diameter are given. In Question 10 we find the midpoints of the sides of a quadrilateral whose vertices are given. It is further seen that the figure formed by joining those midpoints is a parallelogram. 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.