Given the figure determine the value of the unknown segment, #x#?

enter image source here

1 Answer
Aug 23, 2016

#:. x = 7sqrt(6)~~17.15#

Explanation:

The tangent secant theorem states that if a tangent segment and a secant segment are drawn to a circle from the same external point, then the product of the lengths of the internal and external parts of the secant segment equals the square of the length of the tangent segment.

In the given picture, this gives us

#PA^2=PC*CF#

#=> x^2 = 7*42 = 294#

#:. x = sqrt(294) = 7sqrt(6)~~17.15#