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National and Regional Contests
Poland Contests
Poland - Second Round
1989 Poland - Second Round
6
6
Part of
1989 Poland - Second Round
Problems
(1)
two tangential quads leadto a third tangential quad
Source: Polish MO Recond Round 1989 p6
9/9/2024
In the triangle
A
B
C
ABC
A
BC
, the lines
C
P
CP
CP
,
A
P
AP
A
P
,
B
P
BP
BP
are drawn through the internal point
P
P
P
and intersect the sides
A
B
AB
A
B
,
B
C
BC
BC
,
C
A
CA
C
A
at points
K
K
K
,
L
L
L
,
M
M
M
, respectively. Prove that if circles can be inscribed in the quadrilaterals
A
K
P
M
AKPM
A
K
PM
and
K
B
L
P
KBLP
K
B
L
P
, then a circle can also be inscribed in the quadrilateral
L
C
M
P
LCMP
L
CMP
.
geometry
tangential