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by Daniel Pedoe (University of Minnesota)
Year of Award: 1968
Publication Information: The American Mathematical Monthly, vol. 74, 1967, pp. 627-640
Summary: The theorem under discussion is
"If four circles in a plane touch each other externally, and if \(r_1, r_2, r_3\), and \(r_4\) denote their curvatures (that is the reciprocals of their radii), then the following relation holds
\[2(r_1^2 + r_2^2 + r_3^2 + r_4^2) = (r_1 + r_2 + r_3 + r_4)^2\]
."
About the Author: (from The American Mathematical Monthly, vol. 74, (1967)) Daniel Pedoe was at the University of Minnesota at the time of publication.