8 (a) P and Q are points on the circumference of a circle, centre O, radius R cm. The minor arc PQ = 20 cm and POQˆ = 48°. (i) Show that R = 23.9, correct to one decimal place. (ii) Calculate the area of the minor sector POQ. (iii) The minor sector POQ is removed from the circle and the remaining major sector is shaped to form an open cone of radius r cm. (b) [The curved surface area of a cone is πrl, where l is the slant height] Cone A has radius 7.5 cm and height 4 cm. (i) Calculate the curved surface area of cone A. (ii) Cone B is geometrically similar to cone A. The ratio curved surface area of cone A : curved surface area of cone B is 64 : 25 . Find the height of cone B.