Five teachers were hired at Oakdale Middle School at the beginning of the 2005 school year. The performance of each teacher was

For the circle centered at X, as illustrated:

Draw a diameter that runs parallel to chord AB, as depicted in the figure.

Given that the diameter and AB are parallel, the line segment XC, which intersects AB at midpoint C, will be at a right angle to AB.

Thus, triangle XCB forms a right triangle. Consequently, using the Pythagorean theorem, the length of CX is

units.


The answer is: 8 units