17. Find the length of the required tangent

$TP$ 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 9 $cm$ and the length of $OT$ passing through $E$ is 41 $cm$, calculate the length of $AB$.