Intersecting Circles and a Right Angle
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Let A, B, C, and D be points on a circle with center O. Let the lines AB and CD meet at M. Let the circumcircles of AOC and DOB meet at K apart from O. Then is
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Contributed by: Jay Warendorff (March 2011)
Open content licensed under CC BY-NC-SA
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See a problem from Russia 1995.
Permanent Citation
"Intersecting Circles and a Right Angle"
http://demonstrations.wolfram.com/IntersectingCirclesAndARightAngle/
Wolfram Demonstrations Project
Published: March 7 2011