(a(i)) \(PQR\) is a right triangle on horizontal ground, right angle \(R\). \(X\) is vertically above \(R\), \(XR=2.8\) m and \(RQ=7.1\) m. The elevation of \(X\) from \(P\) is 21°. Find its elevation from \(Q\). [2]

(a(ii)) Calculate \(PQ\). [3]

(b) In \(KLM\), \(LM=9.1,LK=16.7\) cm, \(\angle LKM=32^\circ\). Calculate acute \(\angle KML\). [3]

(c(i)) Triangle \(ABC\) has \(AB=12.3,AC=21.5\) cm and area \(62.89\text{ cm}^2\). Show acute \(\angle BAC=28.4^\circ\) to 1 decimal place. [2]

(c(ii)) Calculate \(BC\). [3]

(c(iii)) Extend \(AB\) to \(D\) with \(\angle BDC=90^\circ\). Find \(BD\). [3]