In the figure, if \(AC\) and \(BD\) are common tangents to two circles, then prove that \(AC\) \(=\) \(BD\).
Proof:
The lengths of tangents drawn from an exterior point to a circle are .
From above statement, \(PA\) \(=\) and \(PC\) \(=\) .
Subtract the above two equations.
\(PA\) \(-\) \(=\) \(PB\) \(-\)
\(AC\) \(=\) \(BD\)
Hence, proved.