Prove that the lengths of tangents drawn from an external point to a circle are equal. Using the above, prove that PP’ = QQ’ in the figure.

Question

Prove that the lengths of tangents drawn from an external point to
a circle are equal Using the above, prove that PP’ =
QQ’ in the figure

Siddhi · Accepted Answer

P'A=P'Q tangents from external point (1)

also,

AP=AQ tangents from external point (2)

subtracting(1)and (2),

AP-AP'=AQ-AQ'

Therefore, PP'=QQ'