A pond is circular. A straight wooden jetty PQ of length 60m is built across the pond with its ends on the bank. A raft is anchored at a point R on the circumference such that ∠PRQ=90∘. A cable is to be stretched from P to R and then from R to Q.
(i) Prove that the jetty PQ is a diameter of the pond.
(ii) If PR=25m, calculate the length RQ.
(iii) Taking π=722, find the length of fencing required to enclose the entire circular bank of the pond.