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National and Regional Contests
Peru Contests
Peru MO (ONEM)
2021 Peru MO (ONEM)
3
3
Part of
2021 Peru MO (ONEM)
Problems
(1)
3 incircles with radius r
Source: Peru National Olympiad 2021 #3
11/17/2021
Let
M
,
N
,
P
M,N,P
M
,
N
,
P
be points in the sides
B
C
,
A
C
,
A
B
BC,AC,AB
BC
,
A
C
,
A
B
of
△
A
B
C
\triangle ABC
△
A
BC
respectively. The quadrilateral
M
C
N
P
MCNP
MCNP
has an incircle of radius
r
r
r
, if the incircles of
△
B
P
M
\triangle BPM
△
BPM
and
△
A
N
P
\triangle ANP
△
A
NP
also have the radius
r
r
r
. Prove that
A
P
⋅
M
P
=
B
P
⋅
N
P
AP\cdot MP=BP\cdot NP
A
P
⋅
MP
=
BP
⋅
NP
geometry