IMO Shortlist 2009 problem G4
Dodao/la:
arhiva2. travnja 2012. Given a cyclic quadrilateral

, let the diagonals

and

meet at

and the lines

and

meet at

. The midpoints of

and

are

and

, respectively. Show that

is tangent at

to the circle through the points

,

and

.
Proposed by David Monk, United Kingdom
%V0
Given a cyclic quadrilateral $ABCD$, let the diagonals $AC$ and $BD$ meet at $E$ and the lines $AD$ and $BC$ meet at $F$. The midpoints of $AB$ and $CD$ are $G$ and $H$, respectively. Show that $EF$ is tangent at $E$ to the circle through the points $E$, $G$ and $H$.
Proposed by David Monk, United Kingdom
Izvor: Međunarodna matematička olimpijada, shortlist 2009
Komentari:
fini_keksi, 24. ožujka 2023. 12:06
Zadnja promjena:
fini_keksi, 24. ožujka 2023. 12:06