The radius of a circle is 3 cm and 'O' is its centre. The length of the tangent (in cm) to the circle drawn from a point P, which is at a distance of 5 cm from 'O' is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 4.
In the triangle OQ = 3 cm (radius)
OP = 5 cm
Triangle PQO is the right-angle triangle
By using the Pythagoras' theorem
OP2 = OQ2 + PQ2
⇒ 52 = 32 + PQ2
⇒ 25 - 9 = PQ2
⇒ PQ =
⇒ PQ = 4 cm