Soddy's Formula
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Pat Ballew  
Descartes' Circle Theorem, an example of giving the credit to the wrong person. The formula is about the relation of the radii of four mutually tangent circles and is sometimes called the Kissing Circles Theorem: if four circles are all tangent to each other, then they must intersect at six distinct points. Soddy's name is appropriate for the formula if only for the unique way he presented his discovery in the form of a poem, "The Kiss Precise" (cited here). Later another verse was written by Thorold Gosset to describe the even more general case in N dimensions for N+2 hyperspheres of the Nth dimension.  


Levels:  High School (912), College 
Languages:  English 
Math Topics:  Conic Sections and Circles, History and Biography, Literature/Poetry 
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