Henry Ernest Dudeney/Modern Puzzles/164 - Those Russian Cyclists Again

by : $164$

 * Those Russian Cyclists Again
 * Here is another little experience of the two Russian Army motor-cyclists from the last puzzle.


 * In the section from a map given in the diagram we are shown three long straight roads, forming a right-angled triangle.


 * Dudeney-Modern-Puzzles-164.png


 * The General asked the two men how far it was from $A$ to $B$.
 * Pyotr replied that all he knew was that riding round the triangle, from $A$ to $B$,
 * from there to $C$ and home to $A$, his odometer showed exactly $60$ miles,
 * while Sergei could only say that he happened to know that $C$ was exactly $12$ miles from the road $A$ to $B$ --
 * that is, to the point $D$, as shown by the dotted line.
 * Whereupon the General made a very simple calculation in his head and declared that the distance from $A$ to $B$ must be ...
 * Can the reader discover so easily how far it was?