# Colossal O, Miniscule $$x$$

Geometry Level 2

In the above diagram, $$ABCD$$ is a unit square. A circle $$O$$ with radius $$r$$ has side $$BC$$ as a chord. The distance which the circle intrudes into the square is given as $$x$$, as in the diagram. What is the least value of $$x$$?

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