45. Exemplar exercise problems XIX

From an external point \(P\), two tangents, \(PA\) and \(PB\) are drawn to a circle with centre \(O\). At one point \(E\) on the circle tangent is drawn which intersects \(PA\) and \(PB\) at \(C\) and \(D\), respectively. If \(PA = 10 \ cm\), find the perimeter of the triangle \(PCD\).

 

Perimeter \(=\) \(cm\)