Two circles with radius 1 are externally tangent at B, and have AB and BC as diameters. A tangent to the circle with diameter BC passes

Two circles with radius 1 are externally tangent at B, and have AB and BC as diameters. A tangent to the circle with diameter BC passes through A, and a tangent to the circle with diameter AB passes through C, so that the tangent lines are parallel. Find the distance between the two tangent lines.

 

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