In the given figure,
PQ = 8 cm and OP = 5 cm
OR⊥PQ and so, OR bisects PQ. [∵ Perpendicular drawn from the center to the chord bisects the chord]
⇒PR=RQ=4 cm
In ΔPOR,
OP2=OR2+PR2⇒52=OR2+42
⇒ OR = 3 cm
In ΔTPO and ΔPRO,
∠TOP=∠ROP [common]
and ∠TPO=∠PRO [each 90∘]
∴ΔTPO and ΔPRO are similar. [by AAA Similarity]
⇒TPPO=RPRO⇒TP5=43∴TP=203 cm