A circle
has two parallel tangents
and
. A circle
touches
at
and
at
. A circle
touches
at
,
at
and
at
. The lines
and
meet at
. Show that
is the circumcenter of
%V0
A circle $C$ has two parallel tangents $L'$ and$L"$. A circle $C'$ touches $L'$ at $A$ and $C$ at $X$. A circle $C"$ touches $L"$ at $B$, $C$ at $Y$ and $C'$ at $Z$. The lines $AY$ and $BX$ meet at $Q$. Show that $Q$ is the circumcenter of $XYZ$
Školjka