# Ford Circles

On the math-fun mailing list (where I am a skulker to better mathematicians) Henry Baker shared a delightful 1938 paper by Lester Ford where he constructs tangent circles on adjacent fractions.
I made this applet to help visualize what was going on. Try to find fractions p/q and P/Q for which |pQ-Pq|=1. (And every fraction has an infinite number of adjacent fractions nicely indexed by the integers.) These circles are called Ford circles after this representation.
Lester Ford(later editor of the Monthly and President of the AMS)
American Math Monthly 1938 article

## New Resources

## Discover Topics

Download our apps here: