The Six Circles Theorem

The Six Circles Theorem Fit a circle into one corner of a triangle. Now fit a second circle into a second corner so that it’s tangent to the first circle. Then fit a third circle into the third corner so that it’s tangent to the second circle. Keep this up, cycling among the three corners, and the sixth circle will be tangent to the first one. In this drawing, start with circle 1 in the lower left corner and proceed clockwise - circle 6 will end up tangent to circle 1! credit: Greg Ross Image: Wikimedia Commons