5.2.4.30 Various Problems on the Plane

Condition: around a rectangular triangle \ (a b c \) with legs \ (a b = 8 \) and \ (b c = 6 \) a circle is described. The second circle with the center on the segment \ (a b \) applies to the first circle and applies to the hypotenuse \ (a c \). Find the radius of the second circle.