8 (a) In this question you may use the grid below to help you. The point P has position vector (4 2) and the point Q has position vector (8 -3). (i) Find PQ. (ii) Find |PQ| . (iii) Find the equation of the line PQ. (iv) Given that Q is the midpoint of the line PR, find the coordinates of R. (b) In the diagram triangles OAB and OCD are similar. OA = a, OB = b and BC = 4a - b. (i) Express, as simply as possible, in terms of a and/or b (a) AB, (b) AC, (c) CD. (ii) Find, in its simplest form, the ratio (a) perimeter of triangle OAB : perimeter of triangle OCD, (b) area of triangle OAB : area of trapezium ABDC.