The figure consists of a chord, a secant, and a tangent to the circle. The diagram is not drawn to scale.What is the value of x? Round the answer to the nearest unit.

Step-by-step explanation:
From secant theorem, 16^2 = 8(12 + y); where y is the missing length of the secant.
256 = 8(12 + y)
12 + y = 32
y = 32 - 12 = 20
From chord theorem, 4x = 4(20)
x = 20