The length of the tangent drawn to a circle of radius 12 cm from a point 18 cm away from the centre of the circle is:
Answer & explanation
Correct answer: option 2
In triangle AOB,
By using pythagoras theorem,
h² = b² + p²
OA² = OB² + AB²
18² = 12² + AB²
AB² = 324 - 144
AB² = 180
AB = 6√5 cm