Explanation:
So the center of the circle is x. This means any straight line through that point is the diameter of the circle. So the radius is half of the diameter. So if the radius of the circle is 7 inches and line YZ is the diameter, then to find the answer just multiply the radius by 2.
So
7 x 2 = 14
The length of the line YZ is then 14 inches, because the line is the diameter of the circle.