\(TP\) and \(TQ\) are two tangents from the point \(T\) to the circle having its centre at \(O\). \(AB\) is another tangent touching the circle externally at \(E\) intersecting \(TP\) at \(A\) and \(TO\) at \(Q\). If the radius of the circle is 21 \(cm\) and the length of \(OT\) passing through \(E\) is 35 \(cm\), determine the length of \(AB\).
