Form an
arbelos with the two inner
semicirclestangent at point C. Let m denote any
nonnegativereal number. Draw two circles, with
radiim times the radii of the smaller two arbelos semicircles, centered on the arbelos ground line, also tangent to each other at point C and with radius m times the radius of the corresponding small arbelos arc. Any circle centered on the
Schoch line and externally
tangent to the circles is a Woo circle.^{
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