Two equal chords AB and CD of length 14cm are drawn on opposite sides of the centre O of a circle. The perpendicular distance between the two chords is 8cm.
(a) (i) Show that each chord is 4cm away from the centre.
(b) (ii) Calculate the radius of the circle.
(c) (iii) A third chord EF is drawn at a distance of 6cm from the centre. Find the length of EF.
(d) Answer the following questions.