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Two of infinitely many Woo circles (green) all have the center on the Schoch line (cyan)

In geometry, the Woo circles, introduced by Peter Y. Woo, are a set of infinitely many Archimedean circles.


Form an arbelos with the two inner semicircles tangent at point C. Let m denote any nonnegative real number. Draw two circles, with radii m 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. [1]

See also


  1. ^ Thomas Schoch (2007). "Arbelos - The Woo Circles". Retrieved 2008-06-05.