Given: JK tangent, KH=16, HE=12 Find: JK.

Answer: [tex]JK=8[/tex]
Step-by-step explanation:
You can observe in the figure that JK is a tangent and KH is a secant and both intersect at the point K. Then, according to the Intersecting secant-tangent Theorem:
[tex]JK^2=KE*KH[/tex]
You know that:
[tex]KH=KE+HE[/tex]
Then KE is:
[tex]KE=KH-HE[/tex]
[tex]KE=16-12[/tex]
[tex]KE=4[/tex]
Now you can substitute the value of KE and the value of KH into [tex]JK^2=KE*KH[/tex] and solve for JK. Then the result is:
[tex]JK^2=4*16\\JK^2=64\\JK=\sqrt{64}\\JK=8[/tex]
Both intersecting point K, JK is a tangent and KH is a secant. You can use the intersecting secant-tangent Theorem:
JK^2=KH*EK
First you can do
KH=EK+EH
KE=4
Then you can substitute.
JK^2=64
JK=8