MO circles

Juro built the ABCD square with a 12 cm side. In this square, he scattered a quarter circle with a center at point B passing through point A and a semicircle l that had a center at the center of the BC side and passed point B. He would still build a circle that would lie inside the square and touches the quarter circle k, semicircle l, and side AB. Find the radius of such a circle.

Your answer:

r =

cm

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