A tangent is drawn from a point P to a circle, which meets the circle at T such PT= 8 cm. A secant PAB intersects the circles in points A and B. If PA = 5 cm, which is the length (in cm) of the chord AB?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 7.8
Let AB = cm.
By using the tangent secant theorem we get,
PT2 = PA × PB
82 = 5 × (5 + x)
64 = 25 + 5x
5x = 39
x = 7.8 cm.