Compound triangle from a given area

Points \(A,B,P\) lie on a straight line, with \(B\) between \(A\) and \(P\), and \(BC\perp AP\). Given \(AP=18\) cm, \(AC=15\) cm and the area of \(\triangle APC\) is \(81\text{ cm}^2\), find

1. \(BC\),
2. \(CP\),
3. \(\angle CPA\). Give non-exact lengths, areas and other numerical values to 3 significant figures, and angles to 1 decimal place, unless otherwise stated.