OpenSAT

Draw a diagram of the circle and the chord. Draw a perpendicular segment from the center of the circle to the chord. This segment bisects the chord, creating two right triangles. The hypotenuse of each triangle is the radius of the circle, 5, and the length of one leg is half the length of the chord, 4. Using the Pythagorean theorem, we find the length of the other leg, which is the distance from the center of the circle to the chord: $\sqrt{5^2 - 4^2} = \sqrt{25-16} = \sqrt{9} = 3$.