9514 1404 393
Answer:
x = 12
Step-by-step explanation:
The rule here is that the product of the lengths from the external point of intersection (angle vertex) to the intersections with the circle is the same for both secants. The tangent counts as intersecting the circle twice. So, we have ...
(6)(6) = (3)(x)
x = 36/3 = 12 . . . . . divide by the coefficient of x
