Answer:
C. 6
Step-by-step explanation:
The diameter to the circle is 20, so the radius would be 10. When a radius is perpendicular to a chord, the chord is split in half(the radius is the line segment from the center of the circle, it is not fully drawn). Since 16/2 is 8, that is the length on each side of the intersection. Now, you can use the pythagorean theorem to solve for x:
10^2 = 8^2 + x^2
You may recognize this as a scaled up version of a 3-4-5 right triangle, and you can find that x is 6 or C.
