Answer:
20
Step-by-step explanation:
Since the line of length 16 is a tangent to the circle, then the angle between it and the radius is right.
? is the hypotenuse of the right triangle formed.
Using Pythagoras' identity on the right triangle
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is
?² = 12² + 16² = 144 + 256 = 400 ( take the square root of both sides )
? = = 20