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PA and PB are tangents from external point P to a circle with centre O. If PA = 12 cm and the radius is 5 cm, then OP equals
A15 cm
B13 cm
C17 cm
D12 cm
Answer & Solution
Correct answer: B. 13 cm
1. Right triangle OAP right-angled at A.
2. OP squared = OA squared + PA squared = 25 + 144 = 169.
3. OP = 13 cm.
_Source: NCERT Class 10 Mathematics, Ch 10 "Circles", §10.3_
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