IMO Shortlist 1997 problem 7
Dodao/la:
arhiva2. travnja 2012. The lengths of the sides of a convex hexagon
satisfy
,
,
. Prove that:
%V0
The lengths of the sides of a convex hexagon $ABCDEF$ satisfy $AB = BC$, $CD = DE$, $EF = FA$. Prove that:
$$\frac {BC}{BE} + \frac {DE}{DA} + \frac {FA}{FC} \geq \frac {3}{2}.$$
Izvor: Međunarodna matematička olimpijada, shortlist 1997