IMO Shortlist 1986 problem 3
Avg:
Avg:
Let
, and
be three points on the edge of a circular chord such that
is due west of
and
is an equilateral triangle whose side is
meters long. A boy swam from
directly toward
. After covering a distance of
meters, he turned and swam westward, reaching the shore after covering a distance of
meters. If
and
are both positive integers, determine













Izvor: Međunarodna matematička olimpijada, shortlist 1986