I can't find the distance of Q away from AC and AB

8. The diagram shows three particles P, Q, R attached to light rods AB, BC, CA respectively. The rods are rigidly jointed together so that ABC is a right-angled triangle with AB = 8 cm, AC = 6cm and CAB = 90°. The masses (in kg) of P, Q, R, are 2m, 3m, 5m respectively and AP = 75cm, BQ = 7cm, AR = 35cm. (a) Find the distance of the centre of mass of the system from(i) AC, (ii) AB. [9](b) The system is freely suspended from B and hangs in equilibrium. Calculate the angle that AB makes with the vertical.