Step-by-step explanation:
Let the center of the circle be point O.
A right-angled triangle can be drawn using one side of chord X as the base and its height up to point O.
The height of the triangle will be 4 - 2 = 2, and the hypotenuse is the radius of the circle, which is 4.
By Pythagoras' Theorem, 2^2 + (X/2)^2 = 4^2.
So (X/2)^2 = 14, and X = 2√14.
