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National and Regional Contests
Czech Republic Contests
Czech and Slovak Olympiad III A
2023 Czech and Slovak Olympiad III A.
5
5
Part of
2023 Czech and Slovak Olympiad III A.
Problems
(1)
SKMO 2023 P5
Source: czechoslovak national mo round
4/4/2023
In triangle
A
B
C
ABC
A
BC
let
N
,
M
,
P
N, M, P
N
,
M
,
P
be the midpoints of the sides
B
C
,
C
A
,
A
B
BC, CA, AB
BC
,
C
A
,
A
B
and
G
G
G
be the centroid of this triangle. Let the circle circumscribed to
B
G
P
BGP
BGP
intersect the line
M
P
MP
MP
in point
K
K
K
,
P
≠
K
P \neq K
P
=
K
, and the circle circumscribed to
C
G
N
CGN
CGN
intersect the line
M
N
MN
MN
in point
L
L
L
,
N
≠
L
N \neq L
N
=
L
. Prove that
∠
B
A
K
=
∠
C
A
L
\angle BAK = \angle CAL
∠
B
A
K
=
∠
C
A
L
.
geometry