This Figure Has Tangent and Sectant to the Circle?

This is the secant-tangent theorem......it says that.....

The length of the whole secant times the length of its external segment = the square of the length of the tangent....therefore.....

12 * 5  = x^2

60 = x^2       take the square root of both sides

√60 = x

√(4*15) = x

2√15 = x

So The Answer is 85?

Haha! Nevermind CPhill! I got It! :D

$$\\x^2=5*(5+12)\\ x^2=5*17\\ x^2=85\\ x=\sqrt{85}\\ x=9.22$$