Question

What is the length of line segment PQ? 4 units 5 units 6 units 9 units

Answer 1

Answer: The correct option is second. The length of line segment PQ is 5 units.

Explanation:

From the given figure it is noticed that the MN is the tangent to the circle at point M and its length is 6.

The line PQ is the secant line with length x and QN is external secant segment with length 4 .

According to the tangent secant theorem the square of tangent is equal to the product of external secant with the sum of the of secant and external secant.

$MN^2=QN\times PN$

$6^2=4\times (x+4)$

$36=4x+16$

$20=4x$

$x=5$

Therefore, the length of line segment PQ is 5 units.

Answer 2

Hello! 

I was looking for this answer as well, but I took the quiz and got it correct. The answer is 5 units. 

good luck!